Detect and report dataphase overruns. Put the adapter into 'Bit Bucket'

mode when this occurs and allow the target to complete the transaction.
Force a retry on overruns since they are usually caused by termination or
cable problems.

2 files changed, 32 insertions, 2 deletions

diff --git a/sys/dev/aic7xxx/aic7xxx.seq b/sys/dev/aic7xxx/aic7xxx.seq
index 4613d9f..36ff790 100644
--- a/sys/dev/aic7xxx/aic7xxx.seq
+++ b/sys/dev/aic7xxx/aic7xxx.seq
@@ -39,7 +39,7 @@
  *
  *-M************************************************************************/
 
-VERSION AIC7XXX_SEQ_VER "$Id: aic7xxx.seq,v 1.40 1996/05/31 06:30:15 gibbs Exp $"
+VERSION AIC7XXX_SEQ_VER "$Id: aic7xxx.seq,v 1.41 1996/06/08 06:54:06 gibbs Exp $"
 
 #if defined(__NetBSD__)
 #include "../../../../dev/ic/aic7xxxreg.h"
@@ -340,12 +340,29 @@ data_phase_init:
 	or	FLAGS, DPHASE		/* We have seen a data phase */
 
 data_phase_loop:
+/* Guard against overruns */
+	test	SG_COUNT, 0xff jnz data_phase_inbounds
+/*
+ * Turn on 'Bit Bucket' mode, set the transfer count to
+ * 16meg and let the target run until it changes phase.
+ * When the transfer completes, notify the host that we
+ * had an overrun.
+ */
+	or	SXFRCTL1,BITBUCKET
+	mvi	STCNT0,0xff
+	mvi	STCNT1,0xff
+	mvi	STCNT2,0xff
+
+data_phase_inbounds:
 /* If we are the last SG block, don't set wideodd. */
 	cmp	SG_COUNT,0x01 jne data_phase_wideodd
 	and	DMAPARAMS, 0xbf		/* Turn off WIDEODD */
 data_phase_wideodd:
 	mov	DMAPARAMS  call dma
 
+/* Go tell the host about any overruns */
+	test	SXFRCTL1,BITBUCKET jnz data_phase_overrun
+
 /* Exit if we had an underrun */
 	test	SSTAT0,SDONE	jz data_phase_finish /* underrun STCNT != 0 */
 
@@ -447,6 +464,14 @@ data_phase_finish:
 	mov	SCB_RESID_SGCNT, SG_COUNT
 	jmp	ITloop
 
+data_phase_overrun:
+/*
+ * Turn off BITBUCKET mode and notify the host
+ */
+	and	SXFRCTL1,0x7f		/* ~BITBUCKET */
+	mvi	INTSTAT,DATA_OVERRUN
+	jmp	ITloop
+
 /*
  * Command phase.  Set up the DMA registers and let 'er rip.
  */
diff --git a/sys/dev/aic7xxx/aic7xxx_reg.h b/sys/dev/aic7xxx/aic7xxx_reg.h
index 5226dbb..b9cd5d2 100644
--- a/sys/dev/aic7xxx/aic7xxx_reg.h
+++ b/sys/dev/aic7xxx/aic7xxx_reg.h
@@ -28,7 +28,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- *	$Id: aic7xxx_reg.h,v 1.10 1996/05/10 16:28:00 gibbs Exp $
+ *	$Id: aic7xxx_reg.h,v 1.11 1996/05/21 18:32:23 gibbs Exp $
  */
 
 /*
@@ -434,6 +434,11 @@
 						 * when we were expecting
 						 * another msgin byte.
 						 */
+#define			DATA_OVERRUN	0xe1	/*
+						 * Target attempted to write
+						 * beyond the bounds of its
+						 * command.
+						 */
 #define 	BRKADRINT 0x08
 #define		SCSIINT	  0x04
 #define		CMDCMPLT  0x02