Add fix for another quirky behaviour: sending the command after a sync

negotiation sometimes doesn't send all the command data for some reason.
Transfer remaining fifo data, and if that's not enough, pad the command.
This fixes a system reboot during SCSI device probes.  From my NetBSD fix.

Add missing code to start another device when a disconnect occurs.  Also
from NetBSD.

For all other unknown interrupt conditions, print an explanitory message
before rebooting the system.  This will be useful in determining other
reboots if they happen in the driver.  From jonathan@netbsd.org.

1 files changed, 67 insertions, 10 deletions

diff --git a/sys/dev/tc/asc.c b/sys/dev/tc/asc.c
index 714a41e4f39..7246a421457 100644
--- a/sys/dev/tc/asc.c
+++ b/sys/dev/tc/asc.c
@@ -1,3 +1,4 @@
+/*	$OpenBSD: asc.c,v 1.13 1997/07/08 05:29:11 mhitch Exp $	*/
 /*	$NetBSD: asc.c,v 1.31 1996/10/13 01:38:35 christos Exp $	*/
 
 /*-
@@ -972,12 +973,41 @@ again:
 			readback(regs->asc_cmd);
 			goto done;
 
+		case SCSI_PHASE_COMMAND:
+			/*
+			 * This seems to occur after the command is sent
+			 * following sync negotiation.  The device still
+			 * wants more command data.  The fifo appears to
+			 * to still have the unsent data - but the 53C94
+			 * signaled TC.  If the fifo still contains data,
+			 * transfer it, otherwise do a transfer pad.  The
+			 * target should then continue through the rest of
+			 * the phases and complete normally.
+			 */
+			printf("asc_intr: tgt %d command phase TC zero",
+			    asc->target);
+			if ((regs->asc_flags & ASC_FLAGS_FIFO_CNT) != 0) {
+				printf(" with non-empty fifo %d\n",
+				    regs->asc_flags & ASC_FLAGS_FIFO_CNT);
+				regs->asc_cmd = ASC_CMD_XFER_INFO;
+			} else {
+				printf("; padding command\n");
+				ASC_TC_PUT(regs, 0xff);
+				regs->asc_cmd = ASC_CMD_XFER_PAD | ASC_CMD_DMA;
+			}
+			goto done;
+
 		default:
+			printf("asc_intr: target %d, unknown phase 0x%x\n", 
+			  	asc->target, status);
 			goto abort;
 		}
 
-		if (state->script)
+		if (state->script) {
+			printf("asc_intr: target %d, incomplete script %p\n", 
+			  	asc->target, state->script);
 			goto abort;
+		}
 
 		/* check for DMA in progress */
 		ASC_TC_GET(regs, len);
@@ -1187,8 +1217,12 @@ again:
 		unsigned fifo, id, msg;
 
 		fifo = regs->asc_flags & ASC_FLAGS_FIFO_CNT;
-		if (fifo < 2)
+		if (fifo < 2) {
+			printf("asc_intr: target %d, reselect, fifo %d too small for msg\n", 
+			  	asc->target, fifo);
+
 			goto abort;
+		}
 		/* read unencoded SCSI ID and convert to binary */
 		msg = regs->asc_fifo & asc->myidmask;
 		for (id = 0; (msg & 1) == 0; id++)
@@ -1206,8 +1240,11 @@ again:
 		state = &asc->st[id];
 		asc->script = state->script;
 		state->script = (script_t *)0;
-		if (!(state->flags & DISCONN))
+		if (!(state->flags & DISCONN)) {
+			printf("asc_intr: reselect tgt %d, flags 0x%x not disconnected\n",
+			       asc->target, state->flags);
 			goto abort;
+		}
 		state->flags &= ~DISCONN;
 		regs->asc_syn_p = state->sync_period;
 		regs->asc_syn_o = state->sync_offset;
@@ -1217,9 +1254,10 @@ again:
 	}
 
 	/* check if we are being selected as a target */
-	if (ir & (ASC_INT_SEL | ASC_INT_SEL_ATN))
+	if (ir & (ASC_INT_SEL | ASC_INT_SEL_ATN)) {
+			printf("asc_intr: host adaptor selected as target\n");
 		goto abort;
-
+	}
 	/*
 	 * 'ir' must be just ASC_INT_FC.
 	 * This is normal if canceling an ASC_ENABLE_SEL.
@@ -1863,8 +1901,11 @@ asc_msg_in(asc, status, ss, ir)
 			state->msglen = msg;
 			return (1);
 		}
-		if (state->msgcnt >= state->msglen)
+		if (state->msgcnt >= state->msglen) {
+		  	printf("asc: msg_in too big, msgcnt %d msglen %d\n",
+			       state->msgcnt, state->msglen);
 			goto abort;
+		}
 		state->msg_in[state->msgcnt++] = msg;
 
 		/* did we just read the last byte of the message? */
@@ -1988,8 +2029,11 @@ asc_msg_in(asc, status, ss, ir)
 		break;
 
 	case SCSI_DISCONNECT:
-		if (state->flags & DISCONN)
+		if (state->flags & DISCONN) {
+			printf("asc: disconnected target %d disconnecting again\n",
+			    asc->target);
 			goto abort;
+		}
 		state->flags |= DISCONN;
 		regs->asc_cmd = ASC_CMD_MSG_ACPT;
 		readback(regs->asc_cmd);
@@ -2011,6 +2055,8 @@ done:
 	regs->asc_cmd = ASC_CMD_MSG_ACPT;
 	readback(regs->asc_cmd);
 	if (!state->script) {
+	  	printf("asc_msg_in: target %d, no script?\n", asc->target);
+
 	abort:
 #ifdef DEBUG
 		asc_DumpLog("asc_msg_in");
@@ -2028,12 +2074,11 @@ asc_disconnect(asc, status, ss, ir)
 	register asc_softc_t asc;
 	register int status, ss, ir;
 {
-#if  MACH_DDIAGNOSTIC
+	int i;
+#ifdef DIAGNOSTIC
 	/* later Mach driver checks for late asych disconnect here. */
 	register State *state = &asc->st[asc->target];
-#endif
 
-#ifdef DIAGNOSTIC
 	if (!(state->flags & DISCONN)) {
 		printf("asc_disconnect: device %d: DISCONN not set!\n",
 			asc->target);
@@ -2041,6 +2086,18 @@ asc_disconnect(asc, status, ss, ir)
 #endif /*DIAGNOSTIC*/
 	asc->target = -1;
 	asc->state = ASC_STATE_RESEL;
+	/*
+	 * Look for another device that is ready.
+	 * May want to keep last one started and increment for fairness
+	 * rather than always starting at zero.
+	 */
+	for (i = 0; i < ASC_NCMD; i++) {
+		/* don't restart a disconnected command */
+		if (!asc->cmd[i] || asc->st[i].flags & DISCONN)
+			continue;
+		asc_startcmd(asc, i);
+		return (0);
+	}
 	return (1);
 }