summaryrefslogtreecommitdiffstats
path: root/drivers/gpu/drm/drm_atomic_helper.c
blob: 2b430b05f35d9268b41240f3c78cf36c9c8d54ea (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
2193
2194
2195
2196
2197
2198
2199
2200
2201
2202
2203
2204
2205
2206
2207
2208
2209
2210
2211
2212
2213
2214
2215
2216
2217
2218
2219
2220
2221
2222
2223
2224
2225
2226
2227
2228
2229
2230
2231
2232
2233
2234
2235
2236
2237
2238
2239
2240
2241
2242
2243
2244
2245
2246
2247
2248
2249
2250
2251
2252
2253
2254
2255
2256
2257
2258
2259
2260
2261
2262
2263
2264
2265
2266
2267
2268
2269
2270
2271
2272
2273
2274
2275
2276
2277
2278
2279
2280
2281
2282
2283
2284
2285
2286
2287
2288
2289
2290
2291
2292
2293
2294
2295
2296
2297
2298
2299
2300
2301
2302
2303
2304
2305
2306
2307
2308
2309
2310
2311
2312
2313
2314
2315
2316
2317
2318
2319
2320
2321
2322
2323
2324
2325
2326
2327
2328
2329
2330
2331
2332
2333
2334
2335
2336
2337
2338
2339
2340
2341
2342
2343
2344
2345
2346
2347
2348
2349
2350
2351
2352
2353
2354
2355
2356
2357
2358
2359
2360
2361
2362
2363
2364
2365
2366
2367
2368
2369
2370
2371
2372
2373
2374
2375
2376
2377
2378
2379
2380
2381
2382
2383
2384
2385
2386
2387
2388
2389
2390
2391
2392
2393
2394
2395
2396
2397
2398
2399
2400
2401
2402
2403
2404
2405
2406
2407
2408
2409
2410
2411
2412
2413
2414
2415
2416
2417
2418
2419
2420
2421
2422
2423
2424
2425
2426
2427
2428
2429
2430
2431
2432
2433
2434
2435
2436
2437
2438
2439
2440
2441
2442
2443
2444
2445
2446
2447
2448
2449
2450
2451
2452
2453
2454
2455
2456
2457
2458
2459
2460
2461
2462
2463
2464
2465
2466
2467
2468
2469
2470
2471
2472
2473
2474
2475
2476
2477
2478
2479
2480
2481
2482
2483
2484
2485
2486
2487
2488
2489
2490
2491
2492
2493
2494
2495
2496
2497
2498
2499
2500
2501
2502
2503
2504
2505
2506
2507
2508
2509
2510
2511
2512
2513
2514
2515
2516
2517
2518
2519
2520
2521
2522
2523
2524
2525
2526
2527
2528
2529
2530
2531
2532
2533
2534
2535
2536
2537
2538
2539
2540
2541
2542
2543
2544
2545
2546
2547
2548
2549
2550
2551
2552
2553
2554
2555
2556
2557
2558
2559
2560
2561
2562
2563
2564
2565
2566
2567
2568
2569
2570
2571
2572
2573
2574
2575
2576
2577
2578
2579
2580
2581
2582
2583
2584
2585
2586
2587
2588
2589
2590
2591
2592
2593
2594
2595
2596
2597
2598
2599
2600
2601
2602
2603
2604
2605
2606
2607
2608
2609
2610
2611
2612
2613
2614
2615
2616
2617
2618
2619
2620
2621
2622
2623
2624
2625
2626
2627
2628
2629
2630
2631
2632
2633
2634
2635
2636
2637
2638
2639
2640
2641
2642
2643
2644
2645
2646
2647
2648
2649
2650
2651
2652
2653
2654
2655
2656
2657
2658
2659
2660
2661
2662
2663
2664
2665
2666
2667
2668
2669
2670
2671
2672
2673
2674
2675
2676
2677
2678
2679
2680
2681
2682
2683
2684
2685
2686
2687
2688
2689
2690
2691
2692
2693
2694
2695
2696
2697
2698
2699
2700
2701
2702
2703
2704
2705
2706
2707
2708
2709
2710
2711
2712
2713
2714
2715
2716
2717
2718
2719
2720
2721
2722
2723
2724
2725
2726
2727
2728
2729
2730
2731
2732
2733
2734
2735
2736
2737
2738
2739
2740
2741
2742
2743
2744
2745
2746
2747
2748
2749
2750
2751
2752
2753
2754
2755
2756
2757
2758
2759
2760
2761
2762
2763
2764
2765
2766
2767
2768
2769
2770
2771
2772
2773
2774
2775
2776
2777
2778
2779
2780
2781
2782
2783
2784
2785
2786
2787
2788
2789
2790
2791
2792
2793
2794
2795
2796
2797
2798
2799
2800
2801
2802
2803
2804
2805
2806
2807
2808
2809
2810
2811
2812
2813
2814
2815
2816
2817
2818
2819
2820
2821
2822
2823
2824
2825
2826
2827
2828
2829
2830
2831
2832
2833
2834
2835
2836
2837
2838
2839
2840
2841
2842
2843
2844
2845
2846
2847
2848
2849
2850
2851
2852
2853
2854
2855
2856
2857
2858
2859
2860
2861
2862
2863
2864
2865
2866
2867
2868
2869
2870
2871
2872
/*
 * Copyright (C) 2014 Red Hat
 * Copyright (C) 2014 Intel Corp.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 *
 * Authors:
 * Rob Clark <robdclark@gmail.com>
 * Daniel Vetter <daniel.vetter@ffwll.ch>
 */

#include <drm/drmP.h>
#include <drm/drm_atomic.h>
#include <drm/drm_plane_helper.h>
#include <drm/drm_crtc_helper.h>
#include <drm/drm_atomic_helper.h>
#include <linux/fence.h>

/**
 * DOC: overview
 *
 * This helper library provides implementations of check and commit functions on
 * top of the CRTC modeset helper callbacks and the plane helper callbacks. It
 * also provides convenience implementations for the atomic state handling
 * callbacks for drivers which don't need to subclass the drm core structures to
 * add their own additional internal state.
 *
 * This library also provides default implementations for the check callback in
 * drm_atomic_helper_check() and for the commit callback with
 * drm_atomic_helper_commit(). But the individual stages and callbacks are
 * exposed to allow drivers to mix and match and e.g. use the plane helpers only
 * together with a driver private modeset implementation.
 *
 * This library also provides implementations for all the legacy driver
 * interfaces on top of the atomic interface. See drm_atomic_helper_set_config(),
 * drm_atomic_helper_disable_plane(), drm_atomic_helper_disable_plane() and the
 * various functions to implement set_property callbacks. New drivers must not
 * implement these functions themselves but must use the provided helpers.
 *
 * The atomic helper uses the same function table structures as all other
 * modesetting helpers. See the documentation for struct &drm_crtc_helper_funcs,
 * struct &drm_encoder_helper_funcs and struct &drm_connector_helper_funcs. It
 * also shares the struct &drm_plane_helper_funcs function table with the plane
 * helpers.
 */
static void
drm_atomic_helper_plane_changed(struct drm_atomic_state *state,
				struct drm_plane_state *plane_state,
				struct drm_plane *plane)
{
	struct drm_crtc_state *crtc_state;

	if (plane->state->crtc) {
		crtc_state = state->crtc_states[drm_crtc_index(plane->state->crtc)];

		if (WARN_ON(!crtc_state))
			return;

		crtc_state->planes_changed = true;
	}

	if (plane_state->crtc) {
		crtc_state =
			state->crtc_states[drm_crtc_index(plane_state->crtc)];

		if (WARN_ON(!crtc_state))
			return;

		crtc_state->planes_changed = true;
	}
}

static bool
check_pending_encoder_assignment(struct drm_atomic_state *state,
				 struct drm_encoder *new_encoder)
{
	struct drm_connector *connector;
	struct drm_connector_state *conn_state;
	int i;

	for_each_connector_in_state(state, connector, conn_state, i) {
		if (conn_state->best_encoder != new_encoder)
			continue;

		/* encoder already assigned and we're trying to re-steal it! */
		if (connector->state->best_encoder != conn_state->best_encoder)
			return false;
	}

	return true;
}

static struct drm_crtc *
get_current_crtc_for_encoder(struct drm_device *dev,
			     struct drm_encoder *encoder)
{
	struct drm_mode_config *config = &dev->mode_config;
	struct drm_connector *connector;

	WARN_ON(!drm_modeset_is_locked(&config->connection_mutex));

	drm_for_each_connector(connector, dev) {
		if (connector->state->best_encoder != encoder)
			continue;

		return connector->state->crtc;
	}

	return NULL;
}

static void
set_best_encoder(struct drm_atomic_state *state,
		 struct drm_connector_state *conn_state,
		 struct drm_encoder *encoder)
{
	struct drm_crtc_state *crtc_state;
	struct drm_crtc *crtc;

	if (conn_state->best_encoder) {
		/* Unset the encoder_mask in the old crtc state. */
		crtc = conn_state->connector->state->crtc;

		/* A NULL crtc is an error here because we should have
		 *  duplicated a NULL best_encoder when crtc was NULL.
		 * As an exception restoring duplicated atomic state
		 * during resume is allowed, so don't warn when
		 * best_encoder is equal to encoder we intend to set.
		 */
		WARN_ON(!crtc && encoder != conn_state->best_encoder);
		if (crtc) {
			crtc_state = drm_atomic_get_existing_crtc_state(state, crtc);

			crtc_state->encoder_mask &=
				~(1 << drm_encoder_index(conn_state->best_encoder));
		}
	}

	if (encoder) {
		crtc = conn_state->crtc;
		WARN_ON(!crtc);
		if (crtc) {
			crtc_state = drm_atomic_get_existing_crtc_state(state, crtc);

			crtc_state->encoder_mask |=
				1 << drm_encoder_index(encoder);
		}
	}

	conn_state->best_encoder = encoder;
}

static int
steal_encoder(struct drm_atomic_state *state,
	      struct drm_encoder *encoder,
	      struct drm_crtc *encoder_crtc)
{
	struct drm_mode_config *config = &state->dev->mode_config;
	struct drm_crtc_state *crtc_state;
	struct drm_connector *connector;
	struct drm_connector_state *connector_state;

	/*
	 * We can only steal an encoder coming from a connector, which means we
	 * must already hold the connection_mutex.
	 */
	WARN_ON(!drm_modeset_is_locked(&config->connection_mutex));

	DRM_DEBUG_ATOMIC("[ENCODER:%d:%s] in use on [CRTC:%d:%s], stealing it\n",
			 encoder->base.id, encoder->name,
			 encoder_crtc->base.id, encoder_crtc->name);

	crtc_state = drm_atomic_get_crtc_state(state, encoder_crtc);
	if (IS_ERR(crtc_state))
		return PTR_ERR(crtc_state);

	crtc_state->connectors_changed = true;

	list_for_each_entry(connector, &config->connector_list, head) {
		if (connector->state->best_encoder != encoder)
			continue;

		DRM_DEBUG_ATOMIC("Stealing encoder from [CONNECTOR:%d:%s]\n",
				 connector->base.id,
				 connector->name);

		connector_state = drm_atomic_get_connector_state(state,
								 connector);
		if (IS_ERR(connector_state))
			return PTR_ERR(connector_state);

		if (connector_state->best_encoder != encoder)
			continue;

		set_best_encoder(state, connector_state, NULL);
	}

	return 0;
}

static int
update_connector_routing(struct drm_atomic_state *state, int conn_idx)
{
	const struct drm_connector_helper_funcs *funcs;
	struct drm_encoder *new_encoder;
	struct drm_crtc *encoder_crtc;
	struct drm_connector *connector;
	struct drm_connector_state *connector_state;
	struct drm_crtc_state *crtc_state;
	int idx, ret;

	connector = state->connectors[conn_idx];
	connector_state = state->connector_states[conn_idx];

	if (!connector)
		return 0;

	DRM_DEBUG_ATOMIC("Updating routing for [CONNECTOR:%d:%s]\n",
			 connector->base.id,
			 connector->name);

	if (connector->state->crtc != connector_state->crtc) {
		if (connector->state->crtc) {
			idx = drm_crtc_index(connector->state->crtc);

			crtc_state = state->crtc_states[idx];
			crtc_state->connectors_changed = true;
		}

		if (connector_state->crtc) {
			idx = drm_crtc_index(connector_state->crtc);

			crtc_state = state->crtc_states[idx];
			crtc_state->connectors_changed = true;
		}
	}

	if (!connector_state->crtc) {
		DRM_DEBUG_ATOMIC("Disabling [CONNECTOR:%d:%s]\n",
				connector->base.id,
				connector->name);

		set_best_encoder(state, connector_state, NULL);

		return 0;
	}

	funcs = connector->helper_private;

	if (funcs->atomic_best_encoder)
		new_encoder = funcs->atomic_best_encoder(connector,
							 connector_state);
	else
		new_encoder = funcs->best_encoder(connector);

	if (!new_encoder) {
		DRM_DEBUG_ATOMIC("No suitable encoder found for [CONNECTOR:%d:%s]\n",
				 connector->base.id,
				 connector->name);
		return -EINVAL;
	}

	if (!drm_encoder_crtc_ok(new_encoder, connector_state->crtc)) {
		DRM_DEBUG_ATOMIC("[ENCODER:%d:%s] incompatible with [CRTC:%d]\n",
				 new_encoder->base.id,
				 new_encoder->name,
				 connector_state->crtc->base.id);
		return -EINVAL;
	}

	if (new_encoder == connector_state->best_encoder) {
		set_best_encoder(state, connector_state, new_encoder);

		DRM_DEBUG_ATOMIC("[CONNECTOR:%d:%s] keeps [ENCODER:%d:%s], now on [CRTC:%d:%s]\n",
				 connector->base.id,
				 connector->name,
				 new_encoder->base.id,
				 new_encoder->name,
				 connector_state->crtc->base.id,
				 connector_state->crtc->name);

		return 0;
	}

	if (!check_pending_encoder_assignment(state, new_encoder)) {
		DRM_DEBUG_ATOMIC("Encoder for [CONNECTOR:%d:%s] already assigned\n",
				 connector->base.id,
				 connector->name);
		return -EINVAL;
	}

	encoder_crtc = get_current_crtc_for_encoder(state->dev,
						    new_encoder);

	if (encoder_crtc) {
		ret = steal_encoder(state, new_encoder, encoder_crtc);
		if (ret) {
			DRM_DEBUG_ATOMIC("Encoder stealing failed for [CONNECTOR:%d:%s]\n",
					 connector->base.id,
					 connector->name);
			return ret;
		}
	}

	if (WARN_ON(!connector_state->crtc))
		return -EINVAL;

	set_best_encoder(state, connector_state, new_encoder);

	idx = drm_crtc_index(connector_state->crtc);

	crtc_state = state->crtc_states[idx];
	crtc_state->connectors_changed = true;

	DRM_DEBUG_ATOMIC("[CONNECTOR:%d:%s] using [ENCODER:%d:%s] on [CRTC:%d:%s]\n",
			 connector->base.id,
			 connector->name,
			 new_encoder->base.id,
			 new_encoder->name,
			 connector_state->crtc->base.id,
			 connector_state->crtc->name);

	return 0;
}

static int
mode_fixup(struct drm_atomic_state *state)
{
	struct drm_crtc *crtc;
	struct drm_crtc_state *crtc_state;
	struct drm_connector *connector;
	struct drm_connector_state *conn_state;
	int i;
	bool ret;

	for_each_crtc_in_state(state, crtc, crtc_state, i) {
		if (!crtc_state->mode_changed &&
		    !crtc_state->connectors_changed)
			continue;

		drm_mode_copy(&crtc_state->adjusted_mode, &crtc_state->mode);
	}

	for_each_connector_in_state(state, connector, conn_state, i) {
		const struct drm_encoder_helper_funcs *funcs;
		struct drm_encoder *encoder;

		WARN_ON(!!conn_state->best_encoder != !!conn_state->crtc);

		if (!conn_state->crtc || !conn_state->best_encoder)
			continue;

		crtc_state =
			state->crtc_states[drm_crtc_index(conn_state->crtc)];

		/*
		 * Each encoder has at most one connector (since we always steal
		 * it away), so we won't call ->mode_fixup twice.
		 */
		encoder = conn_state->best_encoder;
		funcs = encoder->helper_private;
		if (!funcs)
			continue;

		ret = drm_bridge_mode_fixup(encoder->bridge, &crtc_state->mode,
				&crtc_state->adjusted_mode);
		if (!ret) {
			DRM_DEBUG_ATOMIC("Bridge fixup failed\n");
			return -EINVAL;
		}

		if (funcs->atomic_check) {
			ret = funcs->atomic_check(encoder, crtc_state,
						  conn_state);
			if (ret) {
				DRM_DEBUG_ATOMIC("[ENCODER:%d:%s] check failed\n",
						 encoder->base.id, encoder->name);
				return ret;
			}
		} else if (funcs->mode_fixup) {
			ret = funcs->mode_fixup(encoder, &crtc_state->mode,
						&crtc_state->adjusted_mode);
			if (!ret) {
				DRM_DEBUG_ATOMIC("[ENCODER:%d:%s] fixup failed\n",
						 encoder->base.id, encoder->name);
				return -EINVAL;
			}
		}
	}

	for_each_crtc_in_state(state, crtc, crtc_state, i) {
		const struct drm_crtc_helper_funcs *funcs;

		if (!crtc_state->mode_changed &&
		    !crtc_state->connectors_changed)
			continue;

		funcs = crtc->helper_private;
		if (!funcs->mode_fixup)
			continue;

		ret = funcs->mode_fixup(crtc, &crtc_state->mode,
					&crtc_state->adjusted_mode);
		if (!ret) {
			DRM_DEBUG_ATOMIC("[CRTC:%d:%s] fixup failed\n",
					 crtc->base.id, crtc->name);
			return -EINVAL;
		}
	}

	return 0;
}

/**
 * drm_atomic_helper_check_modeset - validate state object for modeset changes
 * @dev: DRM device
 * @state: the driver state object
 *
 * Check the state object to see if the requested state is physically possible.
 * This does all the crtc and connector related computations for an atomic
 * update and adds any additional connectors needed for full modesets and calls
 * down into ->mode_fixup functions of the driver backend.
 *
 * crtc_state->mode_changed is set when the input mode is changed.
 * crtc_state->connectors_changed is set when a connector is added or
 * removed from the crtc.
 * crtc_state->active_changed is set when crtc_state->active changes,
 * which is used for dpms.
 *
 * IMPORTANT:
 *
 * Drivers which update ->mode_changed (e.g. in their ->atomic_check hooks if a
 * plane update can't be done without a full modeset) _must_ call this function
 * afterwards after that change. It is permitted to call this function multiple
 * times for the same update, e.g. when the ->atomic_check functions depend upon
 * the adjusted dotclock for fifo space allocation and watermark computation.
 *
 * RETURNS
 * Zero for success or -errno
 */
int
drm_atomic_helper_check_modeset(struct drm_device *dev,
				struct drm_atomic_state *state)
{
	struct drm_crtc *crtc;
	struct drm_crtc_state *crtc_state;
	struct drm_connector *connector;
	struct drm_connector_state *connector_state;
	int i, ret;

	for_each_crtc_in_state(state, crtc, crtc_state, i) {
		if (!drm_mode_equal(&crtc->state->mode, &crtc_state->mode)) {
			DRM_DEBUG_ATOMIC("[CRTC:%d:%s] mode changed\n",
					 crtc->base.id, crtc->name);
			crtc_state->mode_changed = true;
		}

		if (crtc->state->enable != crtc_state->enable) {
			DRM_DEBUG_ATOMIC("[CRTC:%d:%s] enable changed\n",
					 crtc->base.id, crtc->name);

			/*
			 * For clarity this assignment is done here, but
			 * enable == 0 is only true when there are no
			 * connectors and a NULL mode.
			 *
			 * The other way around is true as well. enable != 0
			 * iff connectors are attached and a mode is set.
			 */
			crtc_state->mode_changed = true;
			crtc_state->connectors_changed = true;
		}
	}

	for_each_connector_in_state(state, connector, connector_state, i) {
		/*
		 * This only sets crtc->mode_changed for routing changes,
		 * drivers must set crtc->mode_changed themselves when connector
		 * properties need to be updated.
		 */
		ret = update_connector_routing(state, i);
		if (ret)
			return ret;
	}

	/*
	 * After all the routing has been prepared we need to add in any
	 * connector which is itself unchanged, but who's crtc changes it's
	 * configuration. This must be done before calling mode_fixup in case a
	 * crtc only changed its mode but has the same set of connectors.
	 */
	for_each_crtc_in_state(state, crtc, crtc_state, i) {
		bool has_connectors =
			!!crtc_state->connector_mask;

		/*
		 * We must set ->active_changed after walking connectors for
		 * otherwise an update that only changes active would result in
		 * a full modeset because update_connector_routing force that.
		 */
		if (crtc->state->active != crtc_state->active) {
			DRM_DEBUG_ATOMIC("[CRTC:%d:%s] active changed\n",
					 crtc->base.id, crtc->name);
			crtc_state->active_changed = true;
		}

		if (!drm_atomic_crtc_needs_modeset(crtc_state))
			continue;

		DRM_DEBUG_ATOMIC("[CRTC:%d:%s] needs all connectors, enable: %c, active: %c\n",
				 crtc->base.id, crtc->name,
				 crtc_state->enable ? 'y' : 'n',
				 crtc_state->active ? 'y' : 'n');

		ret = drm_atomic_add_affected_connectors(state, crtc);
		if (ret != 0)
			return ret;

		ret = drm_atomic_add_affected_planes(state, crtc);
		if (ret != 0)
			return ret;

		if (crtc_state->enable != has_connectors) {
			DRM_DEBUG_ATOMIC("[CRTC:%d:%s] enabled/connectors mismatch\n",
					 crtc->base.id, crtc->name);

			return -EINVAL;
		}
	}

	return mode_fixup(state);
}
EXPORT_SYMBOL(drm_atomic_helper_check_modeset);

/**
 * drm_atomic_helper_check_planes - validate state object for planes changes
 * @dev: DRM device
 * @state: the driver state object
 *
 * Check the state object to see if the requested state is physically possible.
 * This does all the plane update related checks using by calling into the
 * ->atomic_check hooks provided by the driver.
 *
 * It also sets crtc_state->planes_changed to indicate that a crtc has
 * updated planes.
 *
 * RETURNS
 * Zero for success or -errno
 */
int
drm_atomic_helper_check_planes(struct drm_device *dev,
			       struct drm_atomic_state *state)
{
	struct drm_crtc *crtc;
	struct drm_crtc_state *crtc_state;
	struct drm_plane *plane;
	struct drm_plane_state *plane_state;
	int i, ret = 0;

	for_each_plane_in_state(state, plane, plane_state, i) {
		const struct drm_plane_helper_funcs *funcs;

		funcs = plane->helper_private;

		drm_atomic_helper_plane_changed(state, plane_state, plane);

		if (!funcs || !funcs->atomic_check)
			continue;

		ret = funcs->atomic_check(plane, plane_state);
		if (ret) {
			DRM_DEBUG_ATOMIC("[PLANE:%d:%s] atomic driver check failed\n",
					 plane->base.id, plane->name);
			return ret;
		}
	}

	for_each_crtc_in_state(state, crtc, crtc_state, i) {
		const struct drm_crtc_helper_funcs *funcs;

		funcs = crtc->helper_private;

		if (!funcs || !funcs->atomic_check)
			continue;

		ret = funcs->atomic_check(crtc, state->crtc_states[i]);
		if (ret) {
			DRM_DEBUG_ATOMIC("[CRTC:%d:%s] atomic driver check failed\n",
					 crtc->base.id, crtc->name);
			return ret;
		}
	}

	return ret;
}
EXPORT_SYMBOL(drm_atomic_helper_check_planes);

/**
 * drm_atomic_helper_check - validate state object
 * @dev: DRM device
 * @state: the driver state object
 *
 * Check the state object to see if the requested state is physically possible.
 * Only crtcs and planes have check callbacks, so for any additional (global)
 * checking that a driver needs it can simply wrap that around this function.
 * Drivers without such needs can directly use this as their ->atomic_check()
 * callback.
 *
 * This just wraps the two parts of the state checking for planes and modeset
 * state in the default order: First it calls drm_atomic_helper_check_modeset()
 * and then drm_atomic_helper_check_planes(). The assumption is that the
 * ->atomic_check functions depend upon an updated adjusted_mode.clock to
 * e.g. properly compute watermarks.
 *
 * RETURNS
 * Zero for success or -errno
 */
int drm_atomic_helper_check(struct drm_device *dev,
			    struct drm_atomic_state *state)
{
	int ret;

	ret = drm_atomic_helper_check_modeset(dev, state);
	if (ret)
		return ret;

	ret = drm_atomic_helper_check_planes(dev, state);
	if (ret)
		return ret;

	return ret;
}
EXPORT_SYMBOL(drm_atomic_helper_check);

static void
disable_outputs(struct drm_device *dev, struct drm_atomic_state *old_state)
{
	struct drm_connector *connector;
	struct drm_connector_state *old_conn_state;
	struct drm_crtc *crtc;
	struct drm_crtc_state *old_crtc_state;
	int i;

	for_each_connector_in_state(old_state, connector, old_conn_state, i) {
		const struct drm_encoder_helper_funcs *funcs;
		struct drm_encoder *encoder;

		/* Shut down everything that's in the changeset and currently
		 * still on. So need to check the old, saved state. */
		if (!old_conn_state->crtc)
			continue;

		old_crtc_state = old_state->crtc_states[drm_crtc_index(old_conn_state->crtc)];

		if (!old_crtc_state->active ||
		    !drm_atomic_crtc_needs_modeset(old_conn_state->crtc->state))
			continue;

		encoder = old_conn_state->best_encoder;

		/* We shouldn't get this far if we didn't previously have
		 * an encoder.. but WARN_ON() rather than explode.
		 */
		if (WARN_ON(!encoder))
			continue;

		funcs = encoder->helper_private;

		DRM_DEBUG_ATOMIC("disabling [ENCODER:%d:%s]\n",
				 encoder->base.id, encoder->name);

		/*
		 * Each encoder has at most one connector (since we always steal
		 * it away), so we won't call disable hooks twice.
		 */
		drm_bridge_disable(encoder->bridge);

		/* Right function depends upon target state. */
		if (connector->state->crtc && funcs->prepare)
			funcs->prepare(encoder);
		else if (funcs->disable)
			funcs->disable(encoder);
		else
			funcs->dpms(encoder, DRM_MODE_DPMS_OFF);

		drm_bridge_post_disable(encoder->bridge);
	}

	for_each_crtc_in_state(old_state, crtc, old_crtc_state, i) {
		const struct drm_crtc_helper_funcs *funcs;

		/* Shut down everything that needs a full modeset. */
		if (!drm_atomic_crtc_needs_modeset(crtc->state))
			continue;

		if (!old_crtc_state->active)
			continue;

		funcs = crtc->helper_private;

		DRM_DEBUG_ATOMIC("disabling [CRTC:%d:%s]\n",
				 crtc->base.id, crtc->name);


		/* Right function depends upon target state. */
		if (crtc->state->enable && funcs->prepare)
			funcs->prepare(crtc);
		else if (funcs->disable)
			funcs->disable(crtc);
		else
			funcs->dpms(crtc, DRM_MODE_DPMS_OFF);
	}
}

/**
 * drm_atomic_helper_update_legacy_modeset_state - update legacy modeset state
 * @dev: DRM device
 * @old_state: atomic state object with old state structures
 *
 * This function updates all the various legacy modeset state pointers in
 * connectors, encoders and crtcs. It also updates the timestamping constants
 * used for precise vblank timestamps by calling
 * drm_calc_timestamping_constants().
 *
 * Drivers can use this for building their own atomic commit if they don't have
 * a pure helper-based modeset implementation.
 */
void
drm_atomic_helper_update_legacy_modeset_state(struct drm_device *dev,
					      struct drm_atomic_state *old_state)
{
	struct drm_connector *connector;
	struct drm_connector_state *old_conn_state;
	struct drm_crtc *crtc;
	struct drm_crtc_state *old_crtc_state;
	int i;

	/* clear out existing links and update dpms */
	for_each_connector_in_state(old_state, connector, old_conn_state, i) {
		if (connector->encoder) {
			WARN_ON(!connector->encoder->crtc);

			connector->encoder->crtc = NULL;
			connector->encoder = NULL;
		}

		crtc = connector->state->crtc;
		if ((!crtc && old_conn_state->crtc) ||
		    (crtc && drm_atomic_crtc_needs_modeset(crtc->state))) {
			struct drm_property *dpms_prop =
				dev->mode_config.dpms_property;
			int mode = DRM_MODE_DPMS_OFF;

			if (crtc && crtc->state->active)
				mode = DRM_MODE_DPMS_ON;

			connector->dpms = mode;
			drm_object_property_set_value(&connector->base,
						      dpms_prop, mode);
		}
	}

	/* set new links */
	for_each_connector_in_state(old_state, connector, old_conn_state, i) {
		if (!connector->state->crtc)
			continue;

		if (WARN_ON(!connector->state->best_encoder))
			continue;

		connector->encoder = connector->state->best_encoder;
		connector->encoder->crtc = connector->state->crtc;
	}

	/* set legacy state in the crtc structure */
	for_each_crtc_in_state(old_state, crtc, old_crtc_state, i) {
		struct drm_plane *primary = crtc->primary;

		crtc->mode = crtc->state->mode;
		crtc->enabled = crtc->state->enable;

		if (drm_atomic_get_existing_plane_state(old_state, primary) &&
		    primary->state->crtc == crtc) {
			crtc->x = primary->state->src_x >> 16;
			crtc->y = primary->state->src_y >> 16;
		}

		if (crtc->state->enable)
			drm_calc_timestamping_constants(crtc,
							&crtc->state->adjusted_mode);
	}
}
EXPORT_SYMBOL(drm_atomic_helper_update_legacy_modeset_state);

static void
crtc_set_mode(struct drm_device *dev, struct drm_atomic_state *old_state)
{
	struct drm_crtc *crtc;
	struct drm_crtc_state *old_crtc_state;
	struct drm_connector *connector;
	struct drm_connector_state *old_conn_state;
	int i;

	for_each_crtc_in_state(old_state, crtc, old_crtc_state, i) {
		const struct drm_crtc_helper_funcs *funcs;

		if (!crtc->state->mode_changed)
			continue;

		funcs = crtc->helper_private;

		if (crtc->state->enable && funcs->mode_set_nofb) {
			DRM_DEBUG_ATOMIC("modeset on [CRTC:%d:%s]\n",
					 crtc->base.id, crtc->name);

			funcs->mode_set_nofb(crtc);
		}
	}

	for_each_connector_in_state(old_state, connector, old_conn_state, i) {
		const struct drm_encoder_helper_funcs *funcs;
		struct drm_crtc_state *new_crtc_state;
		struct drm_encoder *encoder;
		struct drm_display_mode *mode, *adjusted_mode;

		if (!connector->state->best_encoder)
			continue;

		encoder = connector->state->best_encoder;
		funcs = encoder->helper_private;
		new_crtc_state = connector->state->crtc->state;
		mode = &new_crtc_state->mode;
		adjusted_mode = &new_crtc_state->adjusted_mode;

		if (!new_crtc_state->mode_changed)
			continue;

		DRM_DEBUG_ATOMIC("modeset on [ENCODER:%d:%s]\n",
				 encoder->base.id, encoder->name);

		/*
		 * Each encoder has at most one connector (since we always steal
		 * it away), so we won't call mode_set hooks twice.
		 */
		if (funcs->mode_set)
			funcs->mode_set(encoder, mode, adjusted_mode);

		drm_bridge_mode_set(encoder->bridge, mode, adjusted_mode);
	}
}

/**
 * drm_atomic_helper_commit_modeset_disables - modeset commit to disable outputs
 * @dev: DRM device
 * @old_state: atomic state object with old state structures
 *
 * This function shuts down all the outputs that need to be shut down and
 * prepares them (if required) with the new mode.
 *
 * For compatibility with legacy crtc helpers this should be called before
 * drm_atomic_helper_commit_planes(), which is what the default commit function
 * does. But drivers with different needs can group the modeset commits together
 * and do the plane commits at the end. This is useful for drivers doing runtime
 * PM since planes updates then only happen when the CRTC is actually enabled.
 */
void drm_atomic_helper_commit_modeset_disables(struct drm_device *dev,
					       struct drm_atomic_state *old_state)
{
	disable_outputs(dev, old_state);

	drm_atomic_helper_update_legacy_modeset_state(dev, old_state);

	crtc_set_mode(dev, old_state);
}
EXPORT_SYMBOL(drm_atomic_helper_commit_modeset_disables);

/**
 * drm_atomic_helper_commit_modeset_enables - modeset commit to enable outputs
 * @dev: DRM device
 * @old_state: atomic state object with old state structures
 *
 * This function enables all the outputs with the new configuration which had to
 * be turned off for the update.
 *
 * For compatibility with legacy crtc helpers this should be called after
 * drm_atomic_helper_commit_planes(), which is what the default commit function
 * does. But drivers with different needs can group the modeset commits together
 * and do the plane commits at the end. This is useful for drivers doing runtime
 * PM since planes updates then only happen when the CRTC is actually enabled.
 */
void drm_atomic_helper_commit_modeset_enables(struct drm_device *dev,
					      struct drm_atomic_state *old_state)
{
	struct drm_crtc *crtc;
	struct drm_crtc_state *old_crtc_state;
	struct drm_connector *connector;
	struct drm_connector_state *old_conn_state;
	int i;

	for_each_crtc_in_state(old_state, crtc, old_crtc_state, i) {
		const struct drm_crtc_helper_funcs *funcs;

		/* Need to filter out CRTCs where only planes change. */
		if (!drm_atomic_crtc_needs_modeset(crtc->state))
			continue;

		if (!crtc->state->active)
			continue;

		funcs = crtc->helper_private;

		if (crtc->state->enable) {
			DRM_DEBUG_ATOMIC("enabling [CRTC:%d:%s]\n",
					 crtc->base.id, crtc->name);

			if (funcs->enable)
				funcs->enable(crtc);
			else
				funcs->commit(crtc);
		}
	}

	for_each_connector_in_state(old_state, connector, old_conn_state, i) {
		const struct drm_encoder_helper_funcs *funcs;
		struct drm_encoder *encoder;

		if (!connector->state->best_encoder)
			continue;

		if (!connector->state->crtc->state->active ||
		    !drm_atomic_crtc_needs_modeset(connector->state->crtc->state))
			continue;

		encoder = connector->state->best_encoder;
		funcs = encoder->helper_private;

		DRM_DEBUG_ATOMIC("enabling [ENCODER:%d:%s]\n",
				 encoder->base.id, encoder->name);

		/*
		 * Each encoder has at most one connector (since we always steal
		 * it away), so we won't call enable hooks twice.
		 */
		drm_bridge_pre_enable(encoder->bridge);

		if (funcs->enable)
			funcs->enable(encoder);
		else
			funcs->commit(encoder);

		drm_bridge_enable(encoder->bridge);
	}
}
EXPORT_SYMBOL(drm_atomic_helper_commit_modeset_enables);

static void wait_for_fences(struct drm_device *dev,
			    struct drm_atomic_state *state)
{
	struct drm_plane *plane;
	struct drm_plane_state *plane_state;
	int i;

	for_each_plane_in_state(state, plane, plane_state, i) {
		if (!plane->state->fence)
			continue;

		WARN_ON(!plane->state->fb);

		fence_wait(plane->state->fence, false);
		fence_put(plane->state->fence);
		plane->state->fence = NULL;
	}
}

/**
 * drm_atomic_helper_framebuffer_changed - check if framebuffer has changed
 * @dev: DRM device
 * @old_state: atomic state object with old state structures
 * @crtc: DRM crtc
 *
 * Checks whether the framebuffer used for this CRTC changes as a result of
 * the atomic update.  This is useful for drivers which cannot use
 * drm_atomic_helper_wait_for_vblanks() and need to reimplement its
 * functionality.
 *
 * Returns:
 * true if the framebuffer changed.
 */
bool drm_atomic_helper_framebuffer_changed(struct drm_device *dev,
					   struct drm_atomic_state *old_state,
					   struct drm_crtc *crtc)
{
	struct drm_plane *plane;
	struct drm_plane_state *old_plane_state;
	int i;

	for_each_plane_in_state(old_state, plane, old_plane_state, i) {
		if (plane->state->crtc != crtc &&
		    old_plane_state->crtc != crtc)
			continue;

		if (plane->state->fb != old_plane_state->fb)
			return true;
	}

	return false;
}
EXPORT_SYMBOL(drm_atomic_helper_framebuffer_changed);

/**
 * drm_atomic_helper_wait_for_vblanks - wait for vblank on crtcs
 * @dev: DRM device
 * @old_state: atomic state object with old state structures
 *
 * Helper to, after atomic commit, wait for vblanks on all effected
 * crtcs (ie. before cleaning up old framebuffers using
 * drm_atomic_helper_cleanup_planes()). It will only wait on crtcs where the
 * framebuffers have actually changed to optimize for the legacy cursor and
 * plane update use-case.
 */
void
drm_atomic_helper_wait_for_vblanks(struct drm_device *dev,
		struct drm_atomic_state *old_state)
{
	struct drm_crtc *crtc;
	struct drm_crtc_state *old_crtc_state;
	int i, ret;

	for_each_crtc_in_state(old_state, crtc, old_crtc_state, i) {
		/* No one cares about the old state, so abuse it for tracking
		 * and store whether we hold a vblank reference (and should do a
		 * vblank wait) in the ->enable boolean. */
		old_crtc_state->enable = false;

		if (!crtc->state->enable)
			continue;

		/* Legacy cursor ioctls are completely unsynced, and userspace
		 * relies on that (by doing tons of cursor updates). */
		if (old_state->legacy_cursor_update)
			continue;

		if (!drm_atomic_helper_framebuffer_changed(dev,
				old_state, crtc))
			continue;

		ret = drm_crtc_vblank_get(crtc);
		if (ret != 0)
			continue;

		old_crtc_state->enable = true;
		old_crtc_state->last_vblank_count = drm_crtc_vblank_count(crtc);
	}

	for_each_crtc_in_state(old_state, crtc, old_crtc_state, i) {
		if (!old_crtc_state->enable)
			continue;

		ret = wait_event_timeout(dev->vblank[i].queue,
				old_crtc_state->last_vblank_count !=
					drm_crtc_vblank_count(crtc),
				msecs_to_jiffies(50));

		drm_crtc_vblank_put(crtc);
	}
}
EXPORT_SYMBOL(drm_atomic_helper_wait_for_vblanks);

/**
 * drm_atomic_helper_commit - commit validated state object
 * @dev: DRM device
 * @state: the driver state object
 * @async: asynchronous commit
 *
 * This function commits a with drm_atomic_helper_check() pre-validated state
 * object. This can still fail when e.g. the framebuffer reservation fails. For
 * now this doesn't implement asynchronous commits.
 *
 * Note that right now this function does not support async commits, and hence
 * driver writers must implement their own version for now. Also note that the
 * default ordering of how the various stages are called is to match the legacy
 * modeset helper library closest. One peculiarity of that is that it doesn't
 * mesh well with runtime PM at all.
 *
 * For drivers supporting runtime PM the recommended sequence is
 *
 *     drm_atomic_helper_commit_modeset_disables(dev, state);
 *
 *     drm_atomic_helper_commit_modeset_enables(dev, state);
 *
 *     drm_atomic_helper_commit_planes(dev, state, true);
 *
 * See the kerneldoc entries for these three functions for more details.
 *
 * RETURNS
 * Zero for success or -errno.
 */
int drm_atomic_helper_commit(struct drm_device *dev,
			     struct drm_atomic_state *state,
			     bool async)
{
	int ret;

	if (async)
		return -EBUSY;

	ret = drm_atomic_helper_prepare_planes(dev, state);
	if (ret)
		return ret;

	/*
	 * This is the point of no return - everything below never fails except
	 * when the hw goes bonghits. Which means we can commit the new state on
	 * the software side now.
	 */

	drm_atomic_helper_swap_state(dev, state);

	/*
	 * Everything below can be run asynchronously without the need to grab
	 * any modeset locks at all under one condition: It must be guaranteed
	 * that the asynchronous work has either been cancelled (if the driver
	 * supports it, which at least requires that the framebuffers get
	 * cleaned up with drm_atomic_helper_cleanup_planes()) or completed
	 * before the new state gets committed on the software side with
	 * drm_atomic_helper_swap_state().
	 *
	 * This scheme allows new atomic state updates to be prepared and
	 * checked in parallel to the asynchronous completion of the previous
	 * update. Which is important since compositors need to figure out the
	 * composition of the next frame right after having submitted the
	 * current layout.
	 */

	wait_for_fences(dev, state);

	drm_atomic_helper_commit_modeset_disables(dev, state);

	drm_atomic_helper_commit_planes(dev, state, false);

	drm_atomic_helper_commit_modeset_enables(dev, state);

	drm_atomic_helper_wait_for_vblanks(dev, state);

	drm_atomic_helper_cleanup_planes(dev, state);

	drm_atomic_state_free(state);

	return 0;
}
EXPORT_SYMBOL(drm_atomic_helper_commit);

/**
 * DOC: implementing async commit
 *
 * For now the atomic helpers don't support async commit directly. If there is
 * real need it could be added though, using the dma-buf fence infrastructure
 * for generic synchronization with outstanding rendering.
 *
 * For now drivers have to implement async commit themselves, with the following
 * sequence being the recommended one:
 *
 * 1. Run drm_atomic_helper_prepare_planes() first. This is the only function
 * which commit needs to call which can fail, so we want to run it first and
 * synchronously.
 *
 * 2. Synchronize with any outstanding asynchronous commit worker threads which
 * might be affected the new state update. This can be done by either cancelling
 * or flushing the work items, depending upon whether the driver can deal with
 * cancelled updates. Note that it is important to ensure that the framebuffer
 * cleanup is still done when cancelling.
 *
 * For sufficient parallelism it is recommended to have a work item per crtc
 * (for updates which don't touch global state) and a global one. Then we only
 * need to synchronize with the crtc work items for changed crtcs and the global
 * work item, which allows nice concurrent updates on disjoint sets of crtcs.
 *
 * 3. The software state is updated synchronously with
 * drm_atomic_helper_swap_state(). Doing this under the protection of all modeset
 * locks means concurrent callers never see inconsistent state. And doing this
 * while it's guaranteed that no relevant async worker runs means that async
 * workers do not need grab any locks. Actually they must not grab locks, for
 * otherwise the work flushing will deadlock.
 *
 * 4. Schedule a work item to do all subsequent steps, using the split-out
 * commit helpers: a) pre-plane commit b) plane commit c) post-plane commit and
 * then cleaning up the framebuffers after the old framebuffer is no longer
 * being displayed.
 */

/**
 * drm_atomic_helper_prepare_planes - prepare plane resources before commit
 * @dev: DRM device
 * @state: atomic state object with new state structures
 *
 * This function prepares plane state, specifically framebuffers, for the new
 * configuration. If any failure is encountered this function will call
 * ->cleanup_fb on any already successfully prepared framebuffer.
 *
 * Returns:
 * 0 on success, negative error code on failure.
 */
int drm_atomic_helper_prepare_planes(struct drm_device *dev,
				     struct drm_atomic_state *state)
{
	int nplanes = dev->mode_config.num_total_plane;
	int ret, i;

	for (i = 0; i < nplanes; i++) {
		const struct drm_plane_helper_funcs *funcs;
		struct drm_plane *plane = state->planes[i];
		struct drm_plane_state *plane_state = state->plane_states[i];

		if (!plane)
			continue;

		funcs = plane->helper_private;

		if (funcs->prepare_fb) {
			ret = funcs->prepare_fb(plane, plane_state);
			if (ret)
				goto fail;
		}
	}

	return 0;

fail:
	for (i--; i >= 0; i--) {
		const struct drm_plane_helper_funcs *funcs;
		struct drm_plane *plane = state->planes[i];
		struct drm_plane_state *plane_state = state->plane_states[i];

		if (!plane)
			continue;

		funcs = plane->helper_private;

		if (funcs->cleanup_fb)
			funcs->cleanup_fb(plane, plane_state);

	}

	return ret;
}
EXPORT_SYMBOL(drm_atomic_helper_prepare_planes);

bool plane_crtc_active(struct drm_plane_state *state)
{
	return state->crtc && state->crtc->state->active;
}

/**
 * drm_atomic_helper_commit_planes - commit plane state
 * @dev: DRM device
 * @old_state: atomic state object with old state structures
 * @active_only: Only commit on active CRTC if set
 *
 * This function commits the new plane state using the plane and atomic helper
 * functions for planes and crtcs. It assumes that the atomic state has already
 * been pushed into the relevant object state pointers, since this step can no
 * longer fail.
 *
 * It still requires the global state object @old_state to know which planes and
 * crtcs need to be updated though.
 *
 * Note that this function does all plane updates across all CRTCs in one step.
 * If the hardware can't support this approach look at
 * drm_atomic_helper_commit_planes_on_crtc() instead.
 *
 * Plane parameters can be updated by applications while the associated CRTC is
 * disabled. The DRM/KMS core will store the parameters in the plane state,
 * which will be available to the driver when the CRTC is turned on. As a result
 * most drivers don't need to be immediately notified of plane updates for a
 * disabled CRTC.
 *
 * Unless otherwise needed, drivers are advised to set the @active_only
 * parameters to true in order not to receive plane update notifications related
 * to a disabled CRTC. This avoids the need to manually ignore plane updates in
 * driver code when the driver and/or hardware can't or just don't need to deal
 * with updates on disabled CRTCs, for example when supporting runtime PM.
 *
 * The drm_atomic_helper_commit() default implementation only sets @active_only
 * to false to most closely match the behaviour of the legacy helpers. This should
 * not be copied blindly by drivers.
 */
void drm_atomic_helper_commit_planes(struct drm_device *dev,
				     struct drm_atomic_state *old_state,
				     bool active_only)
{
	struct drm_crtc *crtc;
	struct drm_crtc_state *old_crtc_state;
	struct drm_plane *plane;
	struct drm_plane_state *old_plane_state;
	int i;

	for_each_crtc_in_state(old_state, crtc, old_crtc_state, i) {
		const struct drm_crtc_helper_funcs *funcs;

		funcs = crtc->helper_private;

		if (!funcs || !funcs->atomic_begin)
			continue;

		if (active_only && !crtc->state->active)
			continue;

		funcs->atomic_begin(crtc, old_crtc_state);
	}

	for_each_plane_in_state(old_state, plane, old_plane_state, i) {
		const struct drm_plane_helper_funcs *funcs;
		bool disabling;

		funcs = plane->helper_private;

		if (!funcs)
			continue;

		disabling = drm_atomic_plane_disabling(plane, old_plane_state);

		if (active_only) {
			/*
			 * Skip planes related to inactive CRTCs. If the plane
			 * is enabled use the state of the current CRTC. If the
			 * plane is being disabled use the state of the old
			 * CRTC to avoid skipping planes being disabled on an
			 * active CRTC.
			 */
			if (!disabling && !plane_crtc_active(plane->state))
				continue;
			if (disabling && !plane_crtc_active(old_plane_state))
				continue;
		}

		/*
		 * Special-case disabling the plane if drivers support it.
		 */
		if (disabling && funcs->atomic_disable)
			funcs->atomic_disable(plane, old_plane_state);
		else if (plane->state->crtc || disabling)
			funcs->atomic_update(plane, old_plane_state);
	}

	for_each_crtc_in_state(old_state, crtc, old_crtc_state, i) {
		const struct drm_crtc_helper_funcs *funcs;

		funcs = crtc->helper_private;

		if (!funcs || !funcs->atomic_flush)
			continue;

		if (active_only && !crtc->state->active)
			continue;

		funcs->atomic_flush(crtc, old_crtc_state);
	}
}
EXPORT_SYMBOL(drm_atomic_helper_commit_planes);

/**
 * drm_atomic_helper_commit_planes_on_crtc - commit plane state for a crtc
 * @old_crtc_state: atomic state object with the old crtc state
 *
 * This function commits the new plane state using the plane and atomic helper
 * functions for planes on the specific crtc. It assumes that the atomic state
 * has already been pushed into the relevant object state pointers, since this
 * step can no longer fail.
 *
 * This function is useful when plane updates should be done crtc-by-crtc
 * instead of one global step like drm_atomic_helper_commit_planes() does.
 *
 * This function can only be savely used when planes are not allowed to move
 * between different CRTCs because this function doesn't handle inter-CRTC
 * depencies. Callers need to ensure that either no such depencies exist,
 * resolve them through ordering of commit calls or through some other means.
 */
void
drm_atomic_helper_commit_planes_on_crtc(struct drm_crtc_state *old_crtc_state)
{
	const struct drm_crtc_helper_funcs *crtc_funcs;
	struct drm_crtc *crtc = old_crtc_state->crtc;
	struct drm_atomic_state *old_state = old_crtc_state->state;
	struct drm_plane *plane;
	unsigned plane_mask;

	plane_mask = old_crtc_state->plane_mask;
	plane_mask |= crtc->state->plane_mask;

	crtc_funcs = crtc->helper_private;
	if (crtc_funcs && crtc_funcs->atomic_begin)
		crtc_funcs->atomic_begin(crtc, old_crtc_state);

	drm_for_each_plane_mask(plane, crtc->dev, plane_mask) {
		struct drm_plane_state *old_plane_state =
			drm_atomic_get_existing_plane_state(old_state, plane);
		const struct drm_plane_helper_funcs *plane_funcs;

		plane_funcs = plane->helper_private;

		if (!old_plane_state || !plane_funcs)
			continue;

		WARN_ON(plane->state->crtc && plane->state->crtc != crtc);

		if (drm_atomic_plane_disabling(plane, old_plane_state) &&
		    plane_funcs->atomic_disable)
			plane_funcs->atomic_disable(plane, old_plane_state);
		else if (plane->state->crtc ||
			 drm_atomic_plane_disabling(plane, old_plane_state))
			plane_funcs->atomic_update(plane, old_plane_state);
	}

	if (crtc_funcs && crtc_funcs->atomic_flush)
		crtc_funcs->atomic_flush(crtc, old_crtc_state);
}
EXPORT_SYMBOL(drm_atomic_helper_commit_planes_on_crtc);

/**
 * drm_atomic_helper_disable_planes_on_crtc - helper to disable CRTC's planes
 * @crtc: CRTC
 * @atomic: if set, synchronize with CRTC's atomic_begin/flush hooks
 *
 * Disables all planes associated with the given CRTC. This can be
 * used for instance in the CRTC helper disable callback to disable
 * all planes before shutting down the display pipeline.
 *
 * If the atomic-parameter is set the function calls the CRTC's
 * atomic_begin hook before and atomic_flush hook after disabling the
 * planes.
 *
 * It is a bug to call this function without having implemented the
 * ->atomic_disable() plane hook.
 */
void drm_atomic_helper_disable_planes_on_crtc(struct drm_crtc *crtc,
					      bool atomic)
{
	const struct drm_crtc_helper_funcs *crtc_funcs =
		crtc->helper_private;
	struct drm_plane *plane;

	if (atomic && crtc_funcs && crtc_funcs->atomic_begin)
		crtc_funcs->atomic_begin(crtc, NULL);

	drm_for_each_plane(plane, crtc->dev) {
		const struct drm_plane_helper_funcs *plane_funcs =
			plane->helper_private;

		if (plane->state->crtc != crtc || !plane_funcs)
			continue;

		WARN_ON(!plane_funcs->atomic_disable);
		if (plane_funcs->atomic_disable)
			plane_funcs->atomic_disable(plane, NULL);
	}

	if (atomic && crtc_funcs && crtc_funcs->atomic_flush)
		crtc_funcs->atomic_flush(crtc, NULL);
}
EXPORT_SYMBOL(drm_atomic_helper_disable_planes_on_crtc);

/**
 * drm_atomic_helper_cleanup_planes - cleanup plane resources after commit
 * @dev: DRM device
 * @old_state: atomic state object with old state structures
 *
 * This function cleans up plane state, specifically framebuffers, from the old
 * configuration. Hence the old configuration must be perserved in @old_state to
 * be able to call this function.
 *
 * This function must also be called on the new state when the atomic update
 * fails at any point after calling drm_atomic_helper_prepare_planes().
 */
void drm_atomic_helper_cleanup_planes(struct drm_device *dev,
				      struct drm_atomic_state *old_state)
{
	struct drm_plane *plane;
	struct drm_plane_state *plane_state;
	int i;

	for_each_plane_in_state(old_state, plane, plane_state, i) {
		const struct drm_plane_helper_funcs *funcs;

		funcs = plane->helper_private;

		if (funcs->cleanup_fb)
			funcs->cleanup_fb(plane, plane_state);
	}
}
EXPORT_SYMBOL(drm_atomic_helper_cleanup_planes);

/**
 * drm_atomic_helper_swap_state - store atomic state into current sw state
 * @dev: DRM device
 * @state: atomic state
 *
 * This function stores the atomic state into the current state pointers in all
 * driver objects. It should be called after all failing steps have been done
 * and succeeded, but before the actual hardware state is committed.
 *
 * For cleanup and error recovery the current state for all changed objects will
 * be swaped into @state.
 *
 * With that sequence it fits perfectly into the plane prepare/cleanup sequence:
 *
 * 1. Call drm_atomic_helper_prepare_planes() with the staged atomic state.
 *
 * 2. Do any other steps that might fail.
 *
 * 3. Put the staged state into the current state pointers with this function.
 *
 * 4. Actually commit the hardware state.
 *
 * 5. Call drm_atomic_helper_cleanup_planes() with @state, which since step 3
 * contains the old state. Also do any other cleanup required with that state.
 */
void drm_atomic_helper_swap_state(struct drm_device *dev,
				  struct drm_atomic_state *state)
{
	int i;

	for (i = 0; i < dev->mode_config.num_connector; i++) {
		struct drm_connector *connector = state->connectors[i];

		if (!connector)
			continue;

		connector->state->state = state;
		swap(state->connector_states[i], connector->state);
		connector->state->state = NULL;
	}

	for (i = 0; i < dev->mode_config.num_crtc; i++) {
		struct drm_crtc *crtc = state->crtcs[i];

		if (!crtc)
			continue;

		crtc->state->state = state;
		swap(state->crtc_states[i], crtc->state);
		crtc->state->state = NULL;
	}

	for (i = 0; i < dev->mode_config.num_total_plane; i++) {
		struct drm_plane *plane = state->planes[i];

		if (!plane)
			continue;

		plane->state->state = state;
		swap(state->plane_states[i], plane->state);
		plane->state->state = NULL;
	}
}
EXPORT_SYMBOL(drm_atomic_helper_swap_state);

/**
 * drm_atomic_helper_update_plane - Helper for primary plane update using atomic
 * @plane: plane object to update
 * @crtc: owning CRTC of owning plane
 * @fb: framebuffer to flip onto plane
 * @crtc_x: x offset of primary plane on crtc
 * @crtc_y: y offset of primary plane on crtc
 * @crtc_w: width of primary plane rectangle on crtc
 * @crtc_h: height of primary plane rectangle on crtc
 * @src_x: x offset of @fb for panning
 * @src_y: y offset of @fb for panning
 * @src_w: width of source rectangle in @fb
 * @src_h: height of source rectangle in @fb
 *
 * Provides a default plane update handler using the atomic driver interface.
 *
 * RETURNS:
 * Zero on success, error code on failure
 */
int drm_atomic_helper_update_plane(struct drm_plane *plane,
				   struct drm_crtc *crtc,
				   struct drm_framebuffer *fb,
				   int crtc_x, int crtc_y,
				   unsigned int crtc_w, unsigned int crtc_h,
				   uint32_t src_x, uint32_t src_y,
				   uint32_t src_w, uint32_t src_h)
{
	struct drm_atomic_state *state;
	struct drm_plane_state *plane_state;
	int ret = 0;

	state = drm_atomic_state_alloc(plane->dev);
	if (!state)
		return -ENOMEM;

	state->acquire_ctx = drm_modeset_legacy_acquire_ctx(crtc);
retry:
	plane_state = drm_atomic_get_plane_state(state, plane);
	if (IS_ERR(plane_state)) {
		ret = PTR_ERR(plane_state);
		goto fail;
	}

	ret = drm_atomic_set_crtc_for_plane(plane_state, crtc);
	if (ret != 0)
		goto fail;
	drm_atomic_set_fb_for_plane(plane_state, fb);
	plane_state->crtc_x = crtc_x;
	plane_state->crtc_y = crtc_y;
	plane_state->crtc_w = crtc_w;
	plane_state->crtc_h = crtc_h;
	plane_state->src_x = src_x;
	plane_state->src_y = src_y;
	plane_state->src_w = src_w;
	plane_state->src_h = src_h;

	if (plane == crtc->cursor)
		state->legacy_cursor_update = true;

	ret = drm_atomic_commit(state);
	if (ret != 0)
		goto fail;

	/* Driver takes ownership of state on successful commit. */
	return 0;
fail:
	if (ret == -EDEADLK)
		goto backoff;

	drm_atomic_state_free(state);

	return ret;
backoff:
	drm_atomic_state_clear(state);
	drm_atomic_legacy_backoff(state);

	/*
	 * Someone might have exchanged the framebuffer while we dropped locks
	 * in the backoff code. We need to fix up the fb refcount tracking the
	 * core does for us.
	 */
	plane->old_fb = plane->fb;

	goto retry;
}
EXPORT_SYMBOL(drm_atomic_helper_update_plane);

/**
 * drm_atomic_helper_disable_plane - Helper for primary plane disable using * atomic
 * @plane: plane to disable
 *
 * Provides a default plane disable handler using the atomic driver interface.
 *
 * RETURNS:
 * Zero on success, error code on failure
 */
int drm_atomic_helper_disable_plane(struct drm_plane *plane)
{
	struct drm_atomic_state *state;
	struct drm_plane_state *plane_state;
	int ret = 0;

	/*
	 * FIXME: Without plane->crtc set we can't get at the implicit legacy
	 * acquire context. The real fix will be to wire the acquire ctx through
	 * everywhere we need it, but meanwhile prevent chaos by just skipping
	 * this noop. The critical case is the cursor ioctls which a) only grab
	 * crtc/cursor-plane locks (so we need the crtc to get at the right
	 * acquire context) and b) can try to disable the plane multiple times.
	 */
	if (!plane->crtc)
		return 0;

	state = drm_atomic_state_alloc(plane->dev);
	if (!state)
		return -ENOMEM;

	state->acquire_ctx = drm_modeset_legacy_acquire_ctx(plane->crtc);
retry:
	plane_state = drm_atomic_get_plane_state(state, plane);
	if (IS_ERR(plane_state)) {
		ret = PTR_ERR(plane_state);
		goto fail;
	}

	if (plane_state->crtc && (plane == plane->crtc->cursor))
		plane_state->state->legacy_cursor_update = true;

	ret = __drm_atomic_helper_disable_plane(plane, plane_state);
	if (ret != 0)
		goto fail;

	ret = drm_atomic_commit(state);
	if (ret != 0)
		goto fail;

	/* Driver takes ownership of state on successful commit. */
	return 0;
fail:
	if (ret == -EDEADLK)
		goto backoff;

	drm_atomic_state_free(state);

	return ret;
backoff:
	drm_atomic_state_clear(state);
	drm_atomic_legacy_backoff(state);

	/*
	 * Someone might have exchanged the framebuffer while we dropped locks
	 * in the backoff code. We need to fix up the fb refcount tracking the
	 * core does for us.
	 */
	plane->old_fb = plane->fb;

	goto retry;
}
EXPORT_SYMBOL(drm_atomic_helper_disable_plane);

/* just used from fb-helper and atomic-helper: */
int __drm_atomic_helper_disable_plane(struct drm_plane *plane,
		struct drm_plane_state *plane_state)
{
	int ret;

	ret = drm_atomic_set_crtc_for_plane(plane_state, NULL);
	if (ret != 0)
		return ret;

	drm_atomic_set_fb_for_plane(plane_state, NULL);
	plane_state->crtc_x = 0;
	plane_state->crtc_y = 0;
	plane_state->crtc_w = 0;
	plane_state->crtc_h = 0;
	plane_state->src_x = 0;
	plane_state->src_y = 0;
	plane_state->src_w = 0;
	plane_state->src_h = 0;

	return 0;
}

static int update_output_state(struct drm_atomic_state *state,
			       struct drm_mode_set *set)
{
	struct drm_device *dev = set->crtc->dev;
	struct drm_crtc *crtc;
	struct drm_crtc_state *crtc_state;
	struct drm_connector *connector;
	struct drm_connector_state *conn_state;
	int ret, i, j;

	ret = drm_modeset_lock(&dev->mode_config.connection_mutex,
			       state->acquire_ctx);
	if (ret)
		return ret;

	/* First grab all affected connector/crtc states. */
	for (i = 0; i < set->num_connectors; i++) {
		conn_state = drm_atomic_get_connector_state(state,
							    set->connectors[i]);
		if (IS_ERR(conn_state))
			return PTR_ERR(conn_state);
	}

	for_each_crtc_in_state(state, crtc, crtc_state, i) {
		ret = drm_atomic_add_affected_connectors(state, crtc);
		if (ret)
			return ret;
	}

	/* Then recompute connector->crtc links and crtc enabling state. */
	for_each_connector_in_state(state, connector, conn_state, i) {
		if (conn_state->crtc == set->crtc) {
			ret = drm_atomic_set_crtc_for_connector(conn_state,
								NULL);
			if (ret)
				return ret;
		}

		for (j = 0; j < set->num_connectors; j++) {
			if (set->connectors[j] == connector) {
				ret = drm_atomic_set_crtc_for_connector(conn_state,
									set->crtc);
				if (ret)
					return ret;
				break;
			}
		}
	}

	for_each_crtc_in_state(state, crtc, crtc_state, i) {
		/* Don't update ->enable for the CRTC in the set_config request,
		 * since a mismatch would indicate a bug in the upper layers.
		 * The actual modeset code later on will catch any
		 * inconsistencies here. */
		if (crtc == set->crtc)
			continue;

		if (!crtc_state->connector_mask) {
			ret = drm_atomic_set_mode_prop_for_crtc(crtc_state,
								NULL);
			if (ret < 0)
				return ret;

			crtc_state->active = false;
		}
	}

	return 0;
}

/**
 * drm_atomic_helper_set_config - set a new config from userspace
 * @set: mode set configuration
 *
 * Provides a default crtc set_config handler using the atomic driver interface.
 *
 * Returns:
 * Returns 0 on success, negative errno numbers on failure.
 */
int drm_atomic_helper_set_config(struct drm_mode_set *set)
{
	struct drm_atomic_state *state;
	struct drm_crtc *crtc = set->crtc;
	int ret = 0;

	state = drm_atomic_state_alloc(crtc->dev);
	if (!state)
		return -ENOMEM;

	state->acquire_ctx = drm_modeset_legacy_acquire_ctx(crtc);
retry:
	ret = __drm_atomic_helper_set_config(set, state);
	if (ret != 0)
		goto fail;

	ret = drm_atomic_commit(state);
	if (ret != 0)
		goto fail;

	/* Driver takes ownership of state on successful commit. */
	return 0;
fail:
	if (ret == -EDEADLK)
		goto backoff;

	drm_atomic_state_free(state);

	return ret;
backoff:
	drm_atomic_state_clear(state);
	drm_atomic_legacy_backoff(state);

	/*
	 * Someone might have exchanged the framebuffer while we dropped locks
	 * in the backoff code. We need to fix up the fb refcount tracking the
	 * core does for us.
	 */
	crtc->primary->old_fb = crtc->primary->fb;

	goto retry;
}
EXPORT_SYMBOL(drm_atomic_helper_set_config);

/* just used from fb-helper and atomic-helper: */
int __drm_atomic_helper_set_config(struct drm_mode_set *set,
		struct drm_atomic_state *state)
{
	struct drm_crtc_state *crtc_state;
	struct drm_plane_state *primary_state;
	struct drm_crtc *crtc = set->crtc;
	int hdisplay, vdisplay;
	int ret;

	crtc_state = drm_atomic_get_crtc_state(state, crtc);
	if (IS_ERR(crtc_state))
		return PTR_ERR(crtc_state);

	primary_state = drm_atomic_get_plane_state(state, crtc->primary);
	if (IS_ERR(primary_state))
		return PTR_ERR(primary_state);

	if (!set->mode) {
		WARN_ON(set->fb);
		WARN_ON(set->num_connectors);

		ret = drm_atomic_set_mode_for_crtc(crtc_state, NULL);
		if (ret != 0)
			return ret;

		crtc_state->active = false;

		ret = drm_atomic_set_crtc_for_plane(primary_state, NULL);
		if (ret != 0)
			return ret;

		drm_atomic_set_fb_for_plane(primary_state, NULL);

		goto commit;
	}

	WARN_ON(!set->fb);
	WARN_ON(!set->num_connectors);

	ret = drm_atomic_set_mode_for_crtc(crtc_state, set->mode);
	if (ret != 0)
		return ret;

	crtc_state->active = true;

	ret = drm_atomic_set_crtc_for_plane(primary_state, crtc);
	if (ret != 0)
		return ret;

	drm_crtc_get_hv_timing(set->mode, &hdisplay, &vdisplay);

	drm_atomic_set_fb_for_plane(primary_state, set->fb);
	primary_state->crtc_x = 0;
	primary_state->crtc_y = 0;
	primary_state->crtc_w = hdisplay;
	primary_state->crtc_h = vdisplay;
	primary_state->src_x = set->x << 16;
	primary_state->src_y = set->y << 16;
	if (primary_state->rotation & (BIT(DRM_ROTATE_90) | BIT(DRM_ROTATE_270))) {
		primary_state->src_w = vdisplay << 16;
		primary_state->src_h = hdisplay << 16;
	} else {
		primary_state->src_w = hdisplay << 16;
		primary_state->src_h = vdisplay << 16;
	}

commit:
	ret = update_output_state(state, set);
	if (ret)
		return ret;

	return 0;
}

/**
 * drm_atomic_helper_disable_all - disable all currently active outputs
 * @dev: DRM device
 * @ctx: lock acquisition context
 *
 * Loops through all connectors, finding those that aren't turned off and then
 * turns them off by setting their DPMS mode to OFF and deactivating the CRTC
 * that they are connected to.
 *
 * This is used for example in suspend/resume to disable all currently active
 * functions when suspending.
 *
 * Note that if callers haven't already acquired all modeset locks this might
 * return -EDEADLK, which must be handled by calling drm_modeset_backoff().
 *
 * Returns:
 * 0 on success or a negative error code on failure.
 *
 * See also:
 * drm_atomic_helper_suspend(), drm_atomic_helper_resume()
 */
int drm_atomic_helper_disable_all(struct drm_device *dev,
				  struct drm_modeset_acquire_ctx *ctx)
{
	struct drm_atomic_state *state;
	struct drm_connector *conn;
	int err;

	state = drm_atomic_state_alloc(dev);
	if (!state)
		return -ENOMEM;

	state->acquire_ctx = ctx;

	drm_for_each_connector(conn, dev) {
		struct drm_crtc *crtc = conn->state->crtc;
		struct drm_crtc_state *crtc_state;

		if (!crtc || conn->dpms != DRM_MODE_DPMS_ON)
			continue;

		crtc_state = drm_atomic_get_crtc_state(state, crtc);
		if (IS_ERR(crtc_state)) {
			err = PTR_ERR(crtc_state);
			goto free;
		}

		crtc_state->active = false;
	}

	err = drm_atomic_commit(state);

free:
	if (err < 0)
		drm_atomic_state_free(state);

	return err;
}
EXPORT_SYMBOL(drm_atomic_helper_disable_all);

/**
 * drm_atomic_helper_suspend - subsystem-level suspend helper
 * @dev: DRM device
 *
 * Duplicates the current atomic state, disables all active outputs and then
 * returns a pointer to the original atomic state to the caller. Drivers can
 * pass this pointer to the drm_atomic_helper_resume() helper upon resume to
 * restore the output configuration that was active at the time the system
 * entered suspend.
 *
 * Note that it is potentially unsafe to use this. The atomic state object
 * returned by this function is assumed to be persistent. Drivers must ensure
 * that this holds true. Before calling this function, drivers must make sure
 * to suspend fbdev emulation so that nothing can be using the device.
 *
 * Returns:
 * A pointer to a copy of the state before suspend on success or an ERR_PTR()-
 * encoded error code on failure. Drivers should store the returned atomic
 * state object and pass it to the drm_atomic_helper_resume() helper upon
 * resume.
 *
 * See also:
 * drm_atomic_helper_duplicate_state(), drm_atomic_helper_disable_all(),
 * drm_atomic_helper_resume()
 */
struct drm_atomic_state *drm_atomic_helper_suspend(struct drm_device *dev)
{
	struct drm_modeset_acquire_ctx ctx;
	struct drm_atomic_state *state;
	int err;

	drm_modeset_acquire_init(&ctx, 0);

retry:
	err = drm_modeset_lock_all_ctx(dev, &ctx);
	if (err < 0) {
		state = ERR_PTR(err);
		goto unlock;
	}

	state = drm_atomic_helper_duplicate_state(dev, &ctx);
	if (IS_ERR(state))
		goto unlock;

	err = drm_atomic_helper_disable_all(dev, &ctx);
	if (err < 0) {
		drm_atomic_state_free(state);
		state = ERR_PTR(err);
		goto unlock;
	}

unlock:
	if (PTR_ERR(state) == -EDEADLK) {
		drm_modeset_backoff(&ctx);
		goto retry;
	}

	drm_modeset_drop_locks(&ctx);
	drm_modeset_acquire_fini(&ctx);
	return state;
}
EXPORT_SYMBOL(drm_atomic_helper_suspend);

/**
 * drm_atomic_helper_resume - subsystem-level resume helper
 * @dev: DRM device
 * @state: atomic state to resume to
 *
 * Calls drm_mode_config_reset() to synchronize hardware and software states,
 * grabs all modeset locks and commits the atomic state object. This can be
 * used in conjunction with the drm_atomic_helper_suspend() helper to
 * implement suspend/resume for drivers that support atomic mode-setting.
 *
 * Returns:
 * 0 on success or a negative error code on failure.
 *
 * See also:
 * drm_atomic_helper_suspend()
 */
int drm_atomic_helper_resume(struct drm_device *dev,
			     struct drm_atomic_state *state)
{
	struct drm_mode_config *config = &dev->mode_config;
	int err;

	drm_mode_config_reset(dev);
	drm_modeset_lock_all(dev);
	state->acquire_ctx = config->acquire_ctx;
	err = drm_atomic_commit(state);
	drm_modeset_unlock_all(dev);

	return err;
}
EXPORT_SYMBOL(drm_atomic_helper_resume);

/**
 * drm_atomic_helper_crtc_set_property - helper for crtc properties
 * @crtc: DRM crtc
 * @property: DRM property
 * @val: value of property
 *
 * Provides a default crtc set_property handler using the atomic driver
 * interface.
 *
 * RETURNS:
 * Zero on success, error code on failure
 */
int
drm_atomic_helper_crtc_set_property(struct drm_crtc *crtc,
				    struct drm_property *property,
				    uint64_t val)
{
	struct drm_atomic_state *state;
	struct drm_crtc_state *crtc_state;
	int ret = 0;

	state = drm_atomic_state_alloc(crtc->dev);
	if (!state)
		return -ENOMEM;

	/* ->set_property is always called with all locks held. */
	state->acquire_ctx = crtc->dev->mode_config.acquire_ctx;
retry:
	crtc_state = drm_atomic_get_crtc_state(state, crtc);
	if (IS_ERR(crtc_state)) {
		ret = PTR_ERR(crtc_state);
		goto fail;
	}

	ret = drm_atomic_crtc_set_property(crtc, crtc_state,
			property, val);
	if (ret)
		goto fail;

	ret = drm_atomic_commit(state);
	if (ret != 0)
		goto fail;

	/* Driver takes ownership of state on successful commit. */
	return 0;
fail:
	if (ret == -EDEADLK)
		goto backoff;

	drm_atomic_state_free(state);

	return ret;
backoff:
	drm_atomic_state_clear(state);
	drm_atomic_legacy_backoff(state);

	goto retry;
}
EXPORT_SYMBOL(drm_atomic_helper_crtc_set_property);

/**
 * drm_atomic_helper_plane_set_property - helper for plane properties
 * @plane: DRM plane
 * @property: DRM property
 * @val: value of property
 *
 * Provides a default plane set_property handler using the atomic driver
 * interface.
 *
 * RETURNS:
 * Zero on success, error code on failure
 */
int
drm_atomic_helper_plane_set_property(struct drm_plane *plane,
				    struct drm_property *property,
				    uint64_t val)
{
	struct drm_atomic_state *state;
	struct drm_plane_state *plane_state;
	int ret = 0;

	state = drm_atomic_state_alloc(plane->dev);
	if (!state)
		return -ENOMEM;

	/* ->set_property is always called with all locks held. */
	state->acquire_ctx = plane->dev->mode_config.acquire_ctx;
retry:
	plane_state = drm_atomic_get_plane_state(state, plane);
	if (IS_ERR(plane_state)) {
		ret = PTR_ERR(plane_state);
		goto fail;
	}

	ret = drm_atomic_plane_set_property(plane, plane_state,
			property, val);
	if (ret)
		goto fail;

	ret = drm_atomic_commit(state);
	if (ret != 0)
		goto fail;

	/* Driver takes ownership of state on successful commit. */
	return 0;
fail:
	if (ret == -EDEADLK)
		goto backoff;

	drm_atomic_state_free(state);

	return ret;
backoff:
	drm_atomic_state_clear(state);
	drm_atomic_legacy_backoff(state);

	goto retry;
}
EXPORT_SYMBOL(drm_atomic_helper_plane_set_property);

/**
 * drm_atomic_helper_connector_set_property - helper for connector properties
 * @connector: DRM connector
 * @property: DRM property
 * @val: value of property
 *
 * Provides a default connector set_property handler using the atomic driver
 * interface.
 *
 * RETURNS:
 * Zero on success, error code on failure
 */
int
drm_atomic_helper_connector_set_property(struct drm_connector *connector,
				    struct drm_property *property,
				    uint64_t val)
{
	struct drm_atomic_state *state;
	struct drm_connector_state *connector_state;
	int ret = 0;

	state = drm_atomic_state_alloc(connector->dev);
	if (!state)
		return -ENOMEM;

	/* ->set_property is always called with all locks held. */
	state->acquire_ctx = connector->dev->mode_config.acquire_ctx;
retry:
	connector_state = drm_atomic_get_connector_state(state, connector);
	if (IS_ERR(connector_state)) {
		ret = PTR_ERR(connector_state);
		goto fail;
	}

	ret = drm_atomic_connector_set_property(connector, connector_state,
			property, val);
	if (ret)
		goto fail;

	ret = drm_atomic_commit(state);
	if (ret != 0)
		goto fail;

	/* Driver takes ownership of state on successful commit. */
	return 0;
fail:
	if (ret == -EDEADLK)
		goto backoff;

	drm_atomic_state_free(state);

	return ret;
backoff:
	drm_atomic_state_clear(state);
	drm_atomic_legacy_backoff(state);

	goto retry;
}
EXPORT_SYMBOL(drm_atomic_helper_connector_set_property);

/**
 * drm_atomic_helper_page_flip - execute a legacy page flip
 * @crtc: DRM crtc
 * @fb: DRM framebuffer
 * @event: optional DRM event to signal upon completion
 * @flags: flip flags for non-vblank sync'ed updates
 *
 * Provides a default page flip implementation using the atomic driver interface.
 *
 * Note that for now so called async page flips (i.e. updates which are not
 * synchronized to vblank) are not supported, since the atomic interfaces have
 * no provisions for this yet.
 *
 * Returns:
 * Returns 0 on success, negative errno numbers on failure.
 */
int drm_atomic_helper_page_flip(struct drm_crtc *crtc,
				struct drm_framebuffer *fb,
				struct drm_pending_vblank_event *event,
				uint32_t flags)
{
	struct drm_plane *plane = crtc->primary;
	struct drm_atomic_state *state;
	struct drm_plane_state *plane_state;
	struct drm_crtc_state *crtc_state;
	int ret = 0;

	if (flags & DRM_MODE_PAGE_FLIP_ASYNC)
		return -EINVAL;

	state = drm_atomic_state_alloc(plane->dev);
	if (!state)
		return -ENOMEM;

	state->acquire_ctx = drm_modeset_legacy_acquire_ctx(crtc);
retry:
	crtc_state = drm_atomic_get_crtc_state(state, crtc);
	if (IS_ERR(crtc_state)) {
		ret = PTR_ERR(crtc_state);
		goto fail;
	}
	crtc_state->event = event;

	plane_state = drm_atomic_get_plane_state(state, plane);
	if (IS_ERR(plane_state)) {
		ret = PTR_ERR(plane_state);
		goto fail;
	}

	ret = drm_atomic_set_crtc_for_plane(plane_state, crtc);
	if (ret != 0)
		goto fail;
	drm_atomic_set_fb_for_plane(plane_state, fb);

	/* Make sure we don't accidentally do a full modeset. */
	state->allow_modeset = false;
	if (!crtc_state->active) {
		DRM_DEBUG_ATOMIC("[CRTC:%d] disabled, rejecting legacy flip\n",
				 crtc->base.id);
		ret = -EINVAL;
		goto fail;
	}

	ret = drm_atomic_async_commit(state);
	if (ret != 0)
		goto fail;

	/* Driver takes ownership of state on successful async commit. */
	return 0;
fail:
	if (ret == -EDEADLK)
		goto backoff;

	drm_atomic_state_free(state);

	return ret;
backoff:
	drm_atomic_state_clear(state);
	drm_atomic_legacy_backoff(state);

	/*
	 * Someone might have exchanged the framebuffer while we dropped locks
	 * in the backoff code. We need to fix up the fb refcount tracking the
	 * core does for us.
	 */
	plane->old_fb = plane->fb;

	goto retry;
}
EXPORT_SYMBOL(drm_atomic_helper_page_flip);

/**
 * drm_atomic_helper_connector_dpms() - connector dpms helper implementation
 * @connector: affected connector
 * @mode: DPMS mode
 *
 * This is the main helper function provided by the atomic helper framework for
 * implementing the legacy DPMS connector interface. It computes the new desired
 * ->active state for the corresponding CRTC (if the connector is enabled) and
 *  updates it.
 *
 * Returns:
 * Returns 0 on success, negative errno numbers on failure.
 */
int drm_atomic_helper_connector_dpms(struct drm_connector *connector,
				     int mode)
{
	struct drm_mode_config *config = &connector->dev->mode_config;
	struct drm_atomic_state *state;
	struct drm_crtc_state *crtc_state;
	struct drm_crtc *crtc;
	struct drm_connector *tmp_connector;
	int ret;
	bool active = false;
	int old_mode = connector->dpms;

	if (mode != DRM_MODE_DPMS_ON)
		mode = DRM_MODE_DPMS_OFF;

	connector->dpms = mode;
	crtc = connector->state->crtc;

	if (!crtc)
		return 0;

	state = drm_atomic_state_alloc(connector->dev);
	if (!state)
		return -ENOMEM;

	state->acquire_ctx = drm_modeset_legacy_acquire_ctx(crtc);
retry:
	crtc_state = drm_atomic_get_crtc_state(state, crtc);
	if (IS_ERR(crtc_state)) {
		ret = PTR_ERR(crtc_state);
		goto fail;
	}

	WARN_ON(!drm_modeset_is_locked(&config->connection_mutex));

	drm_for_each_connector(tmp_connector, connector->dev) {
		if (tmp_connector->state->crtc != crtc)
			continue;

		if (tmp_connector->dpms == DRM_MODE_DPMS_ON) {
			active = true;
			break;
		}
	}
	crtc_state->active = active;

	ret = drm_atomic_commit(state);
	if (ret != 0)
		goto fail;

	/* Driver takes ownership of state on successful commit. */
	return 0;
fail:
	if (ret == -EDEADLK)
		goto backoff;

	connector->dpms = old_mode;
	drm_atomic_state_free(state);

	return ret;
backoff:
	drm_atomic_state_clear(state);
	drm_atomic_legacy_backoff(state);

	goto retry;
}
EXPORT_SYMBOL(drm_atomic_helper_connector_dpms);

/**
 * DOC: atomic state reset and initialization
 *
 * Both the drm core and the atomic helpers assume that there is always the full
 * and correct atomic software state for all connectors, CRTCs and planes
 * available. Which is a bit a problem on driver load and also after system
 * suspend. One way to solve this is to have a hardware state read-out
 * infrastructure which reconstructs the full software state (e.g. the i915
 * driver).
 *
 * The simpler solution is to just reset the software state to everything off,
 * which is easiest to do by calling drm_mode_config_reset(). To facilitate this
 * the atomic helpers provide default reset implementations for all hooks.
 *
 * On the upside the precise state tracking of atomic simplifies system suspend
 * and resume a lot. For drivers using drm_mode_config_reset() a complete recipe
 * is implemented in drm_atomic_helper_suspend() and drm_atomic_helper_resume().
 * For other drivers the building blocks are split out, see the documentation
 * for these functions.
 */

/**
 * drm_atomic_helper_crtc_reset - default ->reset hook for CRTCs
 * @crtc: drm CRTC
 *
 * Resets the atomic state for @crtc by freeing the state pointer (which might
 * be NULL, e.g. at driver load time) and allocating a new empty state object.
 */
void drm_atomic_helper_crtc_reset(struct drm_crtc *crtc)
{
	if (crtc->state)
		drm_property_unreference_blob(crtc->state->mode_blob);
	kfree(crtc->state);
	crtc->state = kzalloc(sizeof(*crtc->state), GFP_KERNEL);

	if (crtc->state)
		crtc->state->crtc = crtc;
}
EXPORT_SYMBOL(drm_atomic_helper_crtc_reset);

/**
 * __drm_atomic_helper_crtc_duplicate_state - copy atomic CRTC state
 * @crtc: CRTC object
 * @state: atomic CRTC state
 *
 * Copies atomic state from a CRTC's current state and resets inferred values.
 * This is useful for drivers that subclass the CRTC state.
 */
void __drm_atomic_helper_crtc_duplicate_state(struct drm_crtc *crtc,
					      struct drm_crtc_state *state)
{
	memcpy(state, crtc->state, sizeof(*state));

	if (state->mode_blob)
		drm_property_reference_blob(state->mode_blob);
	state->mode_changed = false;
	state->active_changed = false;
	state->planes_changed = false;
	state->connectors_changed = false;
	state->event = NULL;
}
EXPORT_SYMBOL(__drm_atomic_helper_crtc_duplicate_state);

/**
 * drm_atomic_helper_crtc_duplicate_state - default state duplicate hook
 * @crtc: drm CRTC
 *
 * Default CRTC state duplicate hook for drivers which don't have their own
 * subclassed CRTC state structure.
 */
struct drm_crtc_state *
drm_atomic_helper_crtc_duplicate_state(struct drm_crtc *crtc)
{
	struct drm_crtc_state *state;

	if (WARN_ON(!crtc->state))
		return NULL;

	state = kmalloc(sizeof(*state), GFP_KERNEL);
	if (state)
		__drm_atomic_helper_crtc_duplicate_state(crtc, state);

	return state;
}
EXPORT_SYMBOL(drm_atomic_helper_crtc_duplicate_state);

/**
 * __drm_atomic_helper_crtc_destroy_state - release CRTC state
 * @crtc: CRTC object
 * @state: CRTC state object to release
 *
 * Releases all resources stored in the CRTC state without actually freeing
 * the memory of the CRTC state. This is useful for drivers that subclass the
 * CRTC state.
 */
void __drm_atomic_helper_crtc_destroy_state(struct drm_crtc *crtc,
					    struct drm_crtc_state *state)
{
	drm_property_unreference_blob(state->mode_blob);
}
EXPORT_SYMBOL(__drm_atomic_helper_crtc_destroy_state);

/**
 * drm_atomic_helper_crtc_destroy_state - default state destroy hook
 * @crtc: drm CRTC
 * @state: CRTC state object to release
 *
 * Default CRTC state destroy hook for drivers which don't have their own
 * subclassed CRTC state structure.
 */
void drm_atomic_helper_crtc_destroy_state(struct drm_crtc *crtc,
					  struct drm_crtc_state *state)
{
	__drm_atomic_helper_crtc_destroy_state(crtc, state);
	kfree(state);
}
EXPORT_SYMBOL(drm_atomic_helper_crtc_destroy_state);

/**
 * drm_atomic_helper_plane_reset - default ->reset hook for planes
 * @plane: drm plane
 *
 * Resets the atomic state for @plane by freeing the state pointer (which might
 * be NULL, e.g. at driver load time) and allocating a new empty state object.
 */
void drm_atomic_helper_plane_reset(struct drm_plane *plane)
{
	if (plane->state && plane->state->fb)
		drm_framebuffer_unreference(plane->state->fb);

	kfree(plane->state);
	plane->state = kzalloc(sizeof(*plane->state), GFP_KERNEL);

	if (plane->state) {
		plane->state->plane = plane;
		plane->state->rotation = BIT(DRM_ROTATE_0);
	}
}
EXPORT_SYMBOL(drm_atomic_helper_plane_reset);

/**
 * __drm_atomic_helper_plane_duplicate_state - copy atomic plane state
 * @plane: plane object
 * @state: atomic plane state
 *
 * Copies atomic state from a plane's current state. This is useful for
 * drivers that subclass the plane state.
 */
void __drm_atomic_helper_plane_duplicate_state(struct drm_plane *plane,
					       struct drm_plane_state *state)
{
	memcpy(state, plane->state, sizeof(*state));

	if (state->fb)
		drm_framebuffer_reference(state->fb);
}
EXPORT_SYMBOL(__drm_atomic_helper_plane_duplicate_state);

/**
 * drm_atomic_helper_plane_duplicate_state - default state duplicate hook
 * @plane: drm plane
 *
 * Default plane state duplicate hook for drivers which don't have their own
 * subclassed plane state structure.
 */
struct drm_plane_state *
drm_atomic_helper_plane_duplicate_state(struct drm_plane *plane)
{
	struct drm_plane_state *state;

	if (WARN_ON(!plane->state))
		return NULL;

	state = kmalloc(sizeof(*state), GFP_KERNEL);
	if (state)
		__drm_atomic_helper_plane_duplicate_state(plane, state);

	return state;
}
EXPORT_SYMBOL(drm_atomic_helper_plane_duplicate_state);

/**
 * __drm_atomic_helper_plane_destroy_state - release plane state
 * @plane: plane object
 * @state: plane state object to release
 *
 * Releases all resources stored in the plane state without actually freeing
 * the memory of the plane state. This is useful for drivers that subclass the
 * plane state.
 */
void __drm_atomic_helper_plane_destroy_state(struct drm_plane *plane,
					     struct drm_plane_state *state)
{
	if (state->fb)
		drm_framebuffer_unreference(state->fb);
}
EXPORT_SYMBOL(__drm_atomic_helper_plane_destroy_state);

/**
 * drm_atomic_helper_plane_destroy_state - default state destroy hook
 * @plane: drm plane
 * @state: plane state object to release
 *
 * Default plane state destroy hook for drivers which don't have their own
 * subclassed plane state structure.
 */
void drm_atomic_helper_plane_destroy_state(struct drm_plane *plane,
					   struct drm_plane_state *state)
{
	__drm_atomic_helper_plane_destroy_state(plane, state);
	kfree(state);
}
EXPORT_SYMBOL(drm_atomic_helper_plane_destroy_state);

/**
 * __drm_atomic_helper_connector_reset - reset state on connector
 * @connector: drm connector
 * @conn_state: connector state to assign
 *
 * Initializes the newly allocated @conn_state and assigns it to
 * #connector ->state, usually required when initializing the drivers
 * or when called from the ->reset hook.
 *
 * This is useful for drivers that subclass the connector state.
 */
void
__drm_atomic_helper_connector_reset(struct drm_connector *connector,
				    struct drm_connector_state *conn_state)
{
	if (conn_state)
		conn_state->connector = connector;

	connector->state = conn_state;
}
EXPORT_SYMBOL(__drm_atomic_helper_connector_reset);

/**
 * drm_atomic_helper_connector_reset - default ->reset hook for connectors
 * @connector: drm connector
 *
 * Resets the atomic state for @connector by freeing the state pointer (which
 * might be NULL, e.g. at driver load time) and allocating a new empty state
 * object.
 */
void drm_atomic_helper_connector_reset(struct drm_connector *connector)
{
	struct drm_connector_state *conn_state =
		kzalloc(sizeof(*conn_state), GFP_KERNEL);

	kfree(connector->state);
	__drm_atomic_helper_connector_reset(connector, conn_state);
}
EXPORT_SYMBOL(drm_atomic_helper_connector_reset);

/**
 * __drm_atomic_helper_connector_duplicate_state - copy atomic connector state
 * @connector: connector object
 * @state: atomic connector state
 *
 * Copies atomic state from a connector's current state. This is useful for
 * drivers that subclass the connector state.
 */
void
__drm_atomic_helper_connector_duplicate_state(struct drm_connector *connector,
					    struct drm_connector_state *state)
{
	memcpy(state, connector->state, sizeof(*state));
}
EXPORT_SYMBOL(__drm_atomic_helper_connector_duplicate_state);

/**
 * drm_atomic_helper_connector_duplicate_state - default state duplicate hook
 * @connector: drm connector
 *
 * Default connector state duplicate hook for drivers which don't have their own
 * subclassed connector state structure.
 */
struct drm_connector_state *
drm_atomic_helper_connector_duplicate_state(struct drm_connector *connector)
{
	struct drm_connector_state *state;

	if (WARN_ON(!connector->state))
		return NULL;

	state = kmalloc(sizeof(*state), GFP_KERNEL);
	if (state)
		__drm_atomic_helper_connector_duplicate_state(connector, state);

	return state;
}
EXPORT_SYMBOL(drm_atomic_helper_connector_duplicate_state);

/**
 * drm_atomic_helper_duplicate_state - duplicate an atomic state object
 * @dev: DRM device
 * @ctx: lock acquisition context
 *
 * Makes a copy of the current atomic state by looping over all objects and
 * duplicating their respective states. This is used for example by suspend/
 * resume support code to save the state prior to suspend such that it can
 * be restored upon resume.
 *
 * Note that this treats atomic state as persistent between save and restore.
 * Drivers must make sure that this is possible and won't result in confusion
 * or erroneous behaviour.
 *
 * Note that if callers haven't already acquired all modeset locks this might
 * return -EDEADLK, which must be handled by calling drm_modeset_backoff().
 *
 * Returns:
 * A pointer to the copy of the atomic state object on success or an
 * ERR_PTR()-encoded error code on failure.
 *
 * See also:
 * drm_atomic_helper_suspend(), drm_atomic_helper_resume()
 */
struct drm_atomic_state *
drm_atomic_helper_duplicate_state(struct drm_device *dev,
				  struct drm_modeset_acquire_ctx *ctx)
{
	struct drm_atomic_state *state;
	struct drm_connector *conn;
	struct drm_plane *plane;
	struct drm_crtc *crtc;
	int err = 0;

	state = drm_atomic_state_alloc(dev);
	if (!state)
		return ERR_PTR(-ENOMEM);

	state->acquire_ctx = ctx;

	drm_for_each_crtc(crtc, dev) {
		struct drm_crtc_state *crtc_state;

		crtc_state = drm_atomic_get_crtc_state(state, crtc);
		if (IS_ERR(crtc_state)) {
			err = PTR_ERR(crtc_state);
			goto free;
		}
	}

	drm_for_each_plane(plane, dev) {
		struct drm_plane_state *plane_state;

		plane_state = drm_atomic_get_plane_state(state, plane);
		if (IS_ERR(plane_state)) {
			err = PTR_ERR(plane_state);
			goto free;
		}
	}

	drm_for_each_connector(conn, dev) {
		struct drm_connector_state *conn_state;

		conn_state = drm_atomic_get_connector_state(state, conn);
		if (IS_ERR(conn_state)) {
			err = PTR_ERR(conn_state);
			goto free;
		}
	}

	/* clear the acquire context so that it isn't accidentally reused */
	state->acquire_ctx = NULL;

free:
	if (err < 0) {
		drm_atomic_state_free(state);
		state = ERR_PTR(err);
	}

	return state;
}
EXPORT_SYMBOL(drm_atomic_helper_duplicate_state);

/**
 * __drm_atomic_helper_connector_destroy_state - release connector state
 * @connector: connector object
 * @state: connector state object to release
 *
 * Releases all resources stored in the connector state without actually
 * freeing the memory of the connector state. This is useful for drivers that
 * subclass the connector state.
 */
void
__drm_atomic_helper_connector_destroy_state(struct drm_connector *connector,
					    struct drm_connector_state *state)
{
	/*
	 * This is currently a placeholder so that drivers that subclass the
	 * state will automatically do the right thing if code is ever added
	 * to this function.
	 */
}
EXPORT_SYMBOL(__drm_atomic_helper_connector_destroy_state);

/**
 * drm_atomic_helper_connector_destroy_state - default state destroy hook
 * @connector: drm connector
 * @state: connector state object to release
 *
 * Default connector state destroy hook for drivers which don't have their own
 * subclassed connector state structure.
 */
void drm_atomic_helper_connector_destroy_state(struct drm_connector *connector,
					  struct drm_connector_state *state)
{
	__drm_atomic_helper_connector_destroy_state(connector, state);
	kfree(state);
}
EXPORT_SYMBOL(drm_atomic_helper_connector_destroy_state);
OpenPOWER on IntegriCloud