Fixes from Thomas Nystrom to fix hanging problems experienced by vr cards

under load.

This patch has been tested by Thomas and other for more than a month now,
and all (known) hangs seem to be solved.

Thomas's explanation of the patch:

*  Fix the problem with the printing of the RX-error.

*  Code from if_fet do better deal with the RX-recovery including a
   timeout of the RX-turnoff.

*  The call to vr_rxeof before vr_rxeoc have been moved to a point
   where the RX-part of the chip is turned off. Otherwise there is a
   window where new data could have been written to the buffer chain
   before the RX-part is turned off. If this happens the chip will see
   a busy rx-buffer. I have no evidence that this have occured but
   god knows what the chip will do in this case!

*  I have added a timeout of the TX-turnoff. I have checked and in
   my 900 MHz system the flags for turnoff (both RX & TX) is seen at
   the first check in the loop.

*  I could see that I got the VR_ISR_DROPPED interrupt sometimes and
   started to thinking about this. I then realized that no recovery is
   needed for this case and therefore I only count it as an rxerror
   (which was not done before).

*  Finally I have changed the FIFO RX threshhold to 128 bytes. When I
   did this the VR_ISR_DROPPED interrupt went away. Theory: The chip
   will receive a complete frame before it tries to write it out to
   memory then the RX threshold is set to store'n'forward. IF the frame
   is large AND the next rx frame also is large AND the bus is busy
   transfering a TX frame to the TX fifo THEN the second received
   frame wont fit in the FIFO and is then dropped. By having the RX
   threshold set to 128 the RX fifo is emptied faster.

MFC after:	5 days

2 files changed, 75 insertions, 34 deletions

diff --git a/sys/pci/if_vr.c b/sys/pci/if_vr.c
index 01b1992..138cba3 100644
--- a/sys/pci/if_vr.c
+++ b/sys/pci/if_vr.c
@@ -1006,33 +1006,23 @@ vr_rxeof(sc)
 		 */
 		if (rxstat & VR_RXSTAT_RXERR) {
 			ifp->if_ierrors++;
-			printf("vr%d: rx error: ", sc->vr_unit);
-			switch(rxstat & 0x000000FF) {
-			case VR_RXSTAT_CRCERR:
-				printf("crc error\n");
-				break;
-			case VR_RXSTAT_FRAMEALIGNERR:
-				printf("frame alignment error\n");
-				break;
-			case VR_RXSTAT_FIFOOFLOW:
-				printf("FIFO overflow\n");
-				break;
-			case VR_RXSTAT_GIANT:
-				printf("received giant packet\n");
-				break;
-			case VR_RXSTAT_RUNT:
-				printf("received runt packet\n");
-				break;
-			case VR_RXSTAT_BUSERR:
-				printf("system bus error\n");
-				break;
-			case VR_RXSTAT_BUFFERR:
-				printf("rx buffer error\n");
-				break;
-			default:
-				printf("unknown rx error\n");
-				break;
-			}
+			printf("vr%d: rx error (%02x):",
+			       sc->vr_unit, rxstat & 0x000000ff);
+			if (rxstat & VR_RXSTAT_CRCERR)
+				printf(" crc error");
+			if (rxstat & VR_RXSTAT_FRAMEALIGNERR)
+				printf(" frame alignment error\n");
+			if (rxstat & VR_RXSTAT_FIFOOFLOW)
+				printf(" FIFO overflow");
+			if (rxstat & VR_RXSTAT_GIANT)
+				printf(" received giant packet");
+			if (rxstat & VR_RXSTAT_RUNT)
+				printf(" received runt packet");
+			if (rxstat & VR_RXSTAT_BUSERR)
+				printf(" system bus error");
+			if (rxstat & VR_RXSTAT_BUFFERR)
+				printf("rx buffer error");
+			printf("\n");
 			vr_newbuf(sc, cur_rx, m);
 			continue;
 		}
@@ -1069,9 +1059,29 @@ static void
 vr_rxeoc(sc)
 	struct vr_softc		*sc;
 {
+	struct ifnet		*ifp;
+	int			i;
+
+	ifp = &sc->arpcom.ac_if;
+
+	ifp->if_ierrors++;
+
+	VR_CLRBIT16(sc, VR_COMMAND, VR_CMD_RX_ON);	
+        DELAY(10000);
+
+	for (i = 0x400;
+	     i && (CSR_READ_2(sc, VR_COMMAND) & VR_CMD_RX_ON);
+	     i--)
+		;	/* Wait for receiver to stop */
+
+	if (!i) {
+		printf("vr%d: rx shutdown error!\n", sc->vr_unit);
+		sc->vr_flags |= VR_F_RESTART;
+		return;
+		}
 
 	vr_rxeof(sc);
-	VR_CLRBIT16(sc, VR_COMMAND, VR_CMD_RX_ON);
+
 	CSR_WRITE_4(sc, VR_RXADDR, vtophys(sc->vr_cdata.vr_rx_head->vr_ptr));
 	VR_SETBIT16(sc, VR_COMMAND, VR_CMD_RX_ON);
 	VR_SETBIT16(sc, VR_COMMAND, VR_CMD_RX_GO);
@@ -1106,14 +1116,22 @@ vr_txeof(sc)
 	 */
 	while(sc->vr_cdata.vr_tx_head->vr_mbuf != NULL) {
 		u_int32_t		txstat;
+		int			i;
 
 		cur_tx = sc->vr_cdata.vr_tx_head;
 		txstat = cur_tx->vr_ptr->vr_status;
 
 		if ((txstat & VR_TXSTAT_ABRT) ||
 		    (txstat & VR_TXSTAT_UDF)) {
-			while (CSR_READ_2(sc, VR_COMMAND) & VR_CMD_TX_ON)
+			for (i = 0x400;
+			     i && (CSR_READ_2(sc, VR_COMMAND) & VR_CMD_TX_ON);
+			     i--)
 				;	/* Wait for chip to shutdown */
+			if (!i) {
+				printf("vr%d: tx shutdown timeout\n", sc->vr_unit);
+				sc->vr_flags |= VR_F_RESTART;
+				break;
+			}
 			VR_TXOWN(cur_tx) = VR_TXSTAT_OWN;
 			CSR_WRITE_4(sc, VR_TXADDR, vtophys(cur_tx->vr_ptr));
 			break;
@@ -1179,6 +1197,14 @@ vr_tick(xsc)
 
 	sc = xsc;
 	VR_LOCK(sc);
+	if (sc->vr_flags & VR_F_RESTART) {
+		printf("vr%d: restarting\n", sc->vr_unit);
+		vr_stop(sc);
+		vr_reset(sc);
+		vr_init(sc);
+		sc->vr_flags &= ~VR_F_RESTART;
+	}
+
 	mii = device_get_softc(sc->vr_miibus);
 	mii_tick(mii);
 
@@ -1223,10 +1249,22 @@ vr_intr(arg)
 		if (status & VR_ISR_RX_OK)
 			vr_rxeof(sc);
 
+		if (status & VR_ISR_RX_DROPPED) {
+			printf("vr%d: rx packet lost\n", sc->vr_unit);
+			ifp->if_ierrors++;
+			}
+
 		if ((status & VR_ISR_RX_ERR) || (status & VR_ISR_RX_NOBUF) ||
-		    (status & VR_ISR_RX_NOBUF) || (status & VR_ISR_RX_OFLOW) ||
-		    (status & VR_ISR_RX_DROPPED)) {
-			vr_rxeof(sc);
+		    (status & VR_ISR_RX_NOBUF) || (status & VR_ISR_RX_OFLOW)) {
+			printf("vr%d: receive error (%04x)",
+			       sc->vr_unit, status);
+			if (status & VR_ISR_RX_NOBUF)
+				printf(" no buffers");
+			if (status & VR_ISR_RX_OFLOW)
+				printf(" overflow");
+			if (status & VR_ISR_RX_DROPPED)
+				printf(" packet lost");
+			printf("\n");
 			vr_rxeoc(sc);
 		}
 
@@ -1455,13 +1493,13 @@ vr_init(xsc)
 	 * so we must set both.
 	 */
 	VR_CLRBIT(sc, VR_BCR0, VR_BCR0_RX_THRESH);
-	VR_SETBIT(sc, VR_BCR0, VR_BCR0_RXTHRESHSTORENFWD);
+	VR_SETBIT(sc, VR_BCR0, VR_BCR0_RXTHRESH128BYTES);
 
 	VR_CLRBIT(sc, VR_BCR1, VR_BCR1_TX_THRESH);
 	VR_SETBIT(sc, VR_BCR1, VR_BCR1_TXTHRESHSTORENFWD);
 
 	VR_CLRBIT(sc, VR_RXCFG, VR_RXCFG_RX_THRESH);
-	VR_SETBIT(sc, VR_RXCFG, VR_RXTHRESH_STORENFWD);
+	VR_SETBIT(sc, VR_RXCFG, VR_RXTHRESH_128BYTES);
 
 	VR_CLRBIT(sc, VR_TXCFG, VR_TXCFG_TX_THRESH);
 	VR_SETBIT(sc, VR_TXCFG, VR_TXTHRESH_STORENFWD);
diff --git a/sys/pci/if_vrreg.h b/sys/pci/if_vrreg.h
index f747881..b7903c1 100644
--- a/sys/pci/if_vrreg.h
+++ b/sys/pci/if_vrreg.h
@@ -464,12 +464,15 @@ struct vr_softc {
 	u_int8_t		vr_unit;	/* interface number */
 	u_int8_t		vr_type;
 	u_int8_t		vr_revid;	/* Rhine chip revision */
+	u_int8_t                vr_flags;       /* See VR_F_* below */
 	struct vr_list_data	*vr_ldata;
 	struct vr_chain_data	vr_cdata;
 	struct callout_handle	vr_stat_ch;
 	struct mtx		vr_mtx;
 };
 
+#define VR_F_RESTART		0x01		/* Restart unit on next tick */
+
 #define	VR_LOCK(_sc)		mtx_lock(&(_sc)->vr_mtx)
 #define	VR_UNLOCK(_sc)		mtx_unlock(&(_sc)->vr_mtx)