Be even more careful in how we manipulate the QOUTQCNT variable. Now we

do reset it from the QOUTCNT register inside a pause/unpause.  This now happens
once per command complete interrupt in the paging case (one interrupt can be
for multiple completed commands).  I may introduce a counter and do a lazy
update in the future, similar to what is done with the QINCNT.

Enhance the QUEUE FULL condition handling so that the number of openings will
be reduced.  This has become more important now that the driver is faster.
This code really belongs in the gerneric SCSI layer, as will be the case once
3.0 gets the code from the 'SCSI' branch.

Add some #if 0'd out trace code I've been using to help debug sequencer
problems.

Fix the SCB paging problem that I was seeing.  This was only on my 7850
controller and stems from the fact that its QINFIFO can only handle 3bit
SCB identifiers.  This means that you can only have 8 transactions open at
a time with the current paging scheme to these controllers.  The code added
to enforce this is generic in that it tests for the number of relevent bits
that the QINFIFO can store and adjusts the max accordingly.  It may be possible
to come up with a scheme that allows for more than 8 commands at a time, but
I don't know that it is worth the effort simply to fix a low end card.  The
aic7880 still can do 255.

This problem may be related to what Andrey was seeing since I don't have n
aic7770 rev E chip here to test on, but as soon as someone probes one of these
cards with this new code, the dmesg output will tell the whole story.

1 files changed, 93 insertions, 20 deletions

diff --git a/sys/i386/scsi/aic7xxx.c b/sys/i386/scsi/aic7xxx.c
index 7aa272a..058d4aa 100644
--- a/sys/i386/scsi/aic7xxx.c
+++ b/sys/i386/scsi/aic7xxx.c
@@ -32,7 +32,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- *      $Id: aic7xxx.c,v 1.84 1996/11/07 06:39:44 gibbs Exp $
+ *      $Id: aic7xxx.c,v 1.85 1996/11/11 05:24:44 gibbs Exp $
  */
 /*
  * TODO:
@@ -771,14 +771,19 @@ ahc_intr(arg)
 		} 
 
 		if ((ahc->flags & AHC_PAGESCBS) != 0) {
-			if ((ahc->type & AHC_AIC78X0) == 0)
-				pause_sequencer(ahc);
+			pause_sequencer(ahc);
 
-			/* We've emptied the Queue */
-			ahc_outb(ahc, QOUTQCNT, 0);
+			/*
+			 * We've emptied the Queue, so reset our
+			 * QOUTQCNT variable to the current QOUTCNT
+			 * setting while the sequencer is paused.
+			 * QOUTCNT will most likely be 0, be we have no
+			 * guarantee that the sequencer did not post
+			 * more work just after our last check.
+			 */
+			ahc_outb(ahc, QOUTQCNT, ahc_inb(ahc, QOUTCNT));
 
-			if ((ahc->type & AHC_AIC78X0) == 0)
-				unpause_sequencer(ahc, FALSE);
+			unpause_sequencer(ahc, /*unpause_always*/FALSE);
 		}
 
 		if (int_cleared == 0)
@@ -1206,22 +1211,38 @@ ahc_handle_seqint(ahc, intstat)
 			if (xs->error == XS_NOERROR)
 				xs->error = XS_DRIVER_STUFFUP;
 			break;
+		case SCSI_QUEUE_FULL:
+			if (scb->hscb->control & TAG_ENB) {
+				/*
+				 * The upper level SCSI code in 3.0
+				 * handles this properly...
+				 */
+				struct scsi_link *sc_link;
+
+				sc_link = xs->sc_link;
+				if (sc_link->active > 2
+				 && sc_link->opennings != 0) {
+					/* truncate the opennings */
+					sc_link->opennings = 0;
+					sc_print_addr(sc_link);
+					printf("Tagged openings reduced to "
+					       "%d\n", sc_link->active);
+				}
+				/*
+				 * XXX requeue this unconditionally.
+				 */
+				STAILQ_INSERT_TAIL(&ahc->waiting_scbs, scb,
+						   links);
+				break;
+			}
+			/* Else treat as if it is a BUSY condition */
+			scb->hscb->status = SCSI_BUSY;
+			/* Fall Through... */
 		case SCSI_BUSY:
 			xs->error = XS_BUSY;
 			sc_print_addr(xs->sc_link);
 			printf("Target Busy\n");
 			break;
-		case SCSI_QUEUE_FULL:
-			/*
-			 * The upper level SCSI code will someday
-			 * handle this properly.
-			 */
-			printf("Queue Full\n");
-			/*
-			 * XXX requeue this unconditionally.
-			 */
-			STAILQ_INSERT_HEAD(&ahc->waiting_scbs, scb, links);
-			break;
 		default:
 			sc_print_addr(xs->sc_link);
 			printf("unexpected targ_status: %x\n", hscb->status);
@@ -1371,6 +1392,46 @@ ahc_handle_seqint(ahc, intstat)
 	case MSGIN_PHASEMIS:
 		break;
 #endif
+#if 0
+	case SCB_TRACE_POINT:
+	{
+		/*
+		 * Print out the bus phase
+		 */
+		char	 *phase;
+		u_int8_t scbindex = ahc_inb(ahc, SCB_TAG);
+		u_int8_t lastphase = ahc_inb(ahc, LASTPHASE);
+
+		scb = ahc->scb_data->scbarray[scbindex];
+		sc_print_addr(scb->xs->sc_link);
+
+		switch (lastphase) {
+		case P_DATAOUT:
+			phase = "Data-Out";
+			break;
+		case P_DATAIN:
+			phase = "Data-In";
+			break;
+		case P_COMMAND:
+			phase = "Command";
+			break;
+		case P_MESGOUT:
+			phase = "Message-Out";
+			break;
+		case P_STATUS:
+			phase = "Status";
+			break;
+		case P_MESGIN:
+			phase = "Message-In";
+			break;
+		default:
+			phase = "busfree";
+			break;
+		}
+		printf("- %s\n", phase);
+		break;
+	}
+#endif
 	default:
 		printf("ahc_intr: seqint, "
 		       "intstat == 0x%x, scsisigi = 0x%x\n",
@@ -1720,7 +1781,12 @@ ahc_init(ahc)
 
 	if ((ahc->scb_data->maxhscbs < AHC_SCB_MAX)
 	 && (ahc->flags & AHC_PAGESCBS)) {
-		ahc->scb_data->maxscbs = AHC_SCB_MAX;
+		u_int8_t max_scbid = 255;
+
+		/* Determine the number of valid bits in the FIFOs */
+		ahc_outb(ahc, QINFIFO, max_scbid);
+		max_scbid = ahc_inb(ahc, QINFIFO);
+		ahc->scb_data->maxscbs = MIN(AHC_SCB_MAX, max_scbid + 1);
 		printf("%d/%d SCBs\n", ahc->scb_data->maxhscbs,
 			ahc->scb_data->maxscbs);
 	} else {
@@ -2090,6 +2156,13 @@ ahc_scsi_cmd(xs)
 		if (ahc->tagenable & mask)
 			hscb->control |= TAG_ENB;
 	}
+
+#if 0
+	/* Set the trace flag if this is the target we want to trace */
+	if (ahc->unit == 2 && xs->sc_link->target == 3)
+		hscb->control |= TRACE_SCB;
+#endif
+
 	hscb->tcl = ((xs->sc_link->target << 4) & 0xF0)
 		  | (IS_SCSIBUS_B(ahc,xs->sc_link)? SELBUSB : 0)
 		  | (xs->sc_link->lun & 0x07);
@@ -2490,7 +2563,7 @@ ahc_timeout(arg)
 	 */
 	bus_state = ahc_inb(ahc, LASTPHASE);
 
-	switch(bus_state & PHASE_MASK)
+	switch(bus_state)
 	{
 	case P_DATAOUT:
 		printf("in dataout phase");