Fix a bug in the driver -- under load, the receive unit could become

idle and the driver would not detect the event, requiring userland
to cycle the interface to bring it up again.
The fix consists in adding SIS_IMR_RX_IDLE to the interrupt mask and
add a command in sis_intr() to restart the receiver when this happens.

While at it, make the test of status bits more efficient.

2 files changed, 13 insertions, 14 deletions

diff --git a/sys/pci/if_sis.c b/sys/pci/if_sis.c
index 19f6d32..a924e99 100644
--- a/sys/pci/if_sis.c
+++ b/sys/pci/if_sis.c
@@ -1439,14 +1439,13 @@ static void sis_intr(arg)
 	u_int32_t		status;
 
 	sc = arg;
-	SIS_LOCK(sc);
 	ifp = &sc->arpcom.ac_if;
 
+	SIS_LOCK(sc);
 	/* Supress unwanted interrupts */
 	if (!(ifp->if_flags & IFF_UP)) {
 		sis_stop(sc);
-		SIS_UNLOCK(sc);
-		return;
+		goto done;
 	}
 
 	/* Disable interrupts. */
@@ -1459,20 +1458,19 @@ static void sis_intr(arg)
 		if ((status & SIS_INTRS) == 0)
 			break;
 
-		if ((status & SIS_ISR_TX_DESC_OK) ||
-		    (status & SIS_ISR_TX_ERR) ||
-		    (status & SIS_ISR_TX_OK) ||
-		    (status & SIS_ISR_TX_IDLE))
+		if (status &
+		    (SIS_ISR_TX_DESC_OK | SIS_ISR_TX_ERR |
+		     SIS_ISR_TX_OK | SIS_ISR_TX_IDLE) )
 			sis_txeof(sc);
 
-		if ((status & SIS_ISR_RX_DESC_OK) ||
-		    (status & SIS_ISR_RX_OK))
+		if (status & (SIS_ISR_RX_DESC_OK|SIS_ISR_RX_OK|SIS_ISR_RX_IDLE))
 			sis_rxeof(sc);
 
-		if ((status & SIS_ISR_RX_ERR) ||
-		    (status & SIS_ISR_RX_OFLOW)) {
+		if (status & (SIS_ISR_RX_ERR | SIS_ISR_RX_OFLOW))
 			sis_rxeoc(sc);
-		}
+
+		if (status & (SIS_ISR_RX_IDLE))
+			SIS_SETBIT(sc, SIS_CSR, SIS_CSR_RX_ENABLE);
 
 		if (status & SIS_ISR_SYSERR) {
 			sis_reset(sc);
@@ -1485,7 +1483,7 @@ static void sis_intr(arg)
 
 	if (ifp->if_snd.ifq_head != NULL)
 		sis_start(ifp);
-
+done:
 	SIS_UNLOCK(sc);
 
 	return;
diff --git a/sys/pci/if_sisreg.h b/sys/pci/if_sisreg.h
index 21cb22a..7ac424f 100644
--- a/sys/pci/if_sisreg.h
+++ b/sys/pci/if_sisreg.h
@@ -185,6 +185,7 @@
 #define SIS_INTRS	\
 	(SIS_IMR_RX_OFLOW|SIS_IMR_TX_UFLOW|SIS_IMR_TX_OK|\
 	 SIS_IMR_TX_IDLE|SIS_IMR_RX_OK|SIS_IMR_RX_ERR|\
+	 SIS_IMR_RX_IDLE|\
 	 SIS_IMR_SYSERR)
 
 #define SIS_IER_INTRENB		0x00000001
@@ -306,7 +307,7 @@ struct sis_desc {
 
 #define SIS_LASTDESC(x)		(!((x)->sis_ctl & SIS_CMDSTS_MORE)))
 #define SIS_OWNDESC(x)		((x)->sis_ctl & SIS_CMDSTS_OWN)
-#define SIS_INC(x, y)		(x) = (x + 1) % y
+#define SIS_INC(x, y)		{ if (++(x) == y) x=0 ; }
 #define SIS_RXBYTES(x)		((x)->sis_ctl & SIS_CMDSTS_BUFLEN)
 
 #define SIS_RXSTAT_COLL		0x00010000