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author | Bartlomiej Zolnierkiewicz <bzolnier@gmail.com> | 2007-05-10 00:01:08 +0200 |
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committer | Bartlomiej Zolnierkiewicz <bzolnier@gmail.com> | 2007-05-10 00:01:08 +0200 |
commit | 2d5eaa6dd744a641e75503232a01f52d0768884c (patch) | |
tree | 0736bd00ea3bd032d601d0a676c998cb043b877a /drivers/ide/ide-lib.c | |
parent | 18137207236285989dfc0ee7f929b954199228f3 (diff) | |
download | op-kernel-dev-2d5eaa6dd744a641e75503232a01f52d0768884c.zip op-kernel-dev-2d5eaa6dd744a641e75503232a01f52d0768884c.tar.gz |
ide: rework the code for selecting the best DMA transfer mode (v3)
Depends on the "ide: fix UDMA/MWDMA/SWDMA masks" patch.
* add ide_hwif_t.udma_filter hook for filtering UDMA mask
(use it in alim15x3, hpt366, siimage and serverworks drivers)
* add ide_max_dma_mode() for finding best DMA mode for the device
(loosely based on some older libata-core.c code)
* convert ide_dma_speed() users to use ide_max_dma_mode()
* make ide_rate_filter() take "ide_drive_t *drive" as an argument instead
of "u8 mode" and teach it to how to use UDMA mask to do filtering
* use ide_rate_filter() in hpt366 driver
* remove no longer needed ide_dma_speed() and *_ratemask()
* unexport eighty_ninty_three()
v2:
* rename ->filter_udma_mask to ->udma_filter
[ Suggested by Sergei Shtylyov <sshtylyov@ru.mvista.com>. ]
v3:
* updated for scc_pata driver (fixes XFER_UDMA_6 filtering for user-space
originated transfer mode change requests when 100MHz clock is used)
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Diffstat (limited to 'drivers/ide/ide-lib.c')
-rw-r--r-- | drivers/ide/ide-lib.c | 125 |
1 files changed, 18 insertions, 107 deletions
diff --git a/drivers/ide/ide-lib.c b/drivers/ide/ide-lib.c index 6871931..4557fc5 100644 --- a/drivers/ide/ide-lib.c +++ b/drivers/ide/ide-lib.c @@ -69,123 +69,34 @@ char *ide_xfer_verbose (u8 xfer_rate) EXPORT_SYMBOL(ide_xfer_verbose); /** - * ide_dma_speed - compute DMA speed - * @drive: drive - * @mode: modes available - * - * Checks the drive capabilities and returns the speed to use - * for the DMA transfer. Returns 0 if the drive is incapable - * of DMA transfers. - */ - -u8 ide_dma_speed(ide_drive_t *drive, u8 mode) -{ - struct hd_driveid *id = drive->id; - ide_hwif_t *hwif = HWIF(drive); - u8 ultra_mask, mwdma_mask, swdma_mask; - u8 speed = 0; - - if (drive->media != ide_disk && hwif->atapi_dma == 0) - return 0; - - /* Capable of UltraDMA modes? */ - ultra_mask = id->dma_ultra & hwif->ultra_mask; - - if (!(id->field_valid & 4)) - mode = 0; /* fallback to MW/SW DMA if no UltraDMA */ - - switch (mode) { - case 4: - if (ultra_mask & 0x40) { - speed = XFER_UDMA_6; - break; - } - case 3: - if (ultra_mask & 0x20) { - speed = XFER_UDMA_5; - break; - } - case 2: - if (ultra_mask & 0x10) { - speed = XFER_UDMA_4; - break; - } - if (ultra_mask & 0x08) { - speed = XFER_UDMA_3; - break; - } - case 1: - if (ultra_mask & 0x04) { - speed = XFER_UDMA_2; - break; - } - if (ultra_mask & 0x02) { - speed = XFER_UDMA_1; - break; - } - if (ultra_mask & 0x01) { - speed = XFER_UDMA_0; - break; - } - case 0: - mwdma_mask = id->dma_mword & hwif->mwdma_mask; - - if (mwdma_mask & 0x04) { - speed = XFER_MW_DMA_2; - break; - } - if (mwdma_mask & 0x02) { - speed = XFER_MW_DMA_1; - break; - } - if (mwdma_mask & 0x01) { - speed = XFER_MW_DMA_0; - break; - } - - swdma_mask = id->dma_1word & hwif->swdma_mask; - - if (swdma_mask & 0x04) { - speed = XFER_SW_DMA_2; - break; - } - if (swdma_mask & 0x02) { - speed = XFER_SW_DMA_1; - break; - } - if (swdma_mask & 0x01) { - speed = XFER_SW_DMA_0; - break; - } - } - - return speed; -} -EXPORT_SYMBOL(ide_dma_speed); - - -/** - * ide_rate_filter - return best speed for mode - * @mode: modes available + * ide_rate_filter - filter transfer mode + * @drive: IDE device * @speed: desired speed * - * Given the available DMA/UDMA mode this function returns + * Given the available transfer modes this function returns * the best available speed at or below the speed requested. + * + * FIXME: filter also PIO/SWDMA/MWDMA modes */ -u8 ide_rate_filter (u8 mode, u8 speed) +u8 ide_rate_filter(ide_drive_t *drive, u8 speed) { #ifdef CONFIG_BLK_DEV_IDEDMA - static u8 speed_max[] = { - XFER_MW_DMA_2, XFER_UDMA_2, XFER_UDMA_4, - XFER_UDMA_5, XFER_UDMA_6 - }; + ide_hwif_t *hwif = drive->hwif; + u8 mask = hwif->ultra_mask, mode = XFER_MW_DMA_2; + + if (hwif->udma_filter) + mask = hwif->udma_filter(drive); + + if ((mask & 0x78) && (eighty_ninty_three(drive) == 0)) + mask &= 0x07; + + if (mask) + mode = fls(mask) - 1 + XFER_UDMA_0; // printk("%s: mode 0x%02x, speed 0x%02x\n", __FUNCTION__, mode, speed); - /* So that we remember to update this if new modes appear */ - BUG_ON(mode > 4); - return min(speed, speed_max[mode]); + return min(speed, mode); #else /* !CONFIG_BLK_DEV_IDEDMA */ return min(speed, (u8)XFER_PIO_4); #endif /* CONFIG_BLK_DEV_IDEDMA */ |