sky2: turn off Rx checksum on bad hardware
authorStephen Hemminger <shemminger@linux-foundation.org>
Thu, 8 Mar 2007 20:42:30 +0000 (12:42 -0800)
committerJeff Garzik <jeff@garzik.org>
Fri, 9 Mar 2007 16:51:32 +0000 (11:51 -0500)
On Yukon FE, occasional hardware receive checksum errors are seen.
An early indication of the problem is single bit differences in the two
checksum engines.  Use this as a detection mechanism to turn off Rx
checksumming.

Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
drivers/net/sky2.c

index 53839979cfb8fb1249dc27161b4cab2649fb994c..ab0ab92583fe427a0568cbb87c5571b918909998 100644 (file)
@@ -2165,9 +2165,27 @@ force_update:
                        /* fall through */
 #endif
                case OP_RXCHKS:
-                       skb = sky2->rx_ring[sky2->rx_next].skb;
-                       skb->ip_summed = CHECKSUM_COMPLETE;
-                       skb->csum = status & 0xffff;
+                       if (!sky2->rx_csum)
+                               break;
+
+                       /* Both checksum counters are programmed to start at
+                        * the same offset, so unless there is a problem they
+                        * should match. This failure is an early indication that
+                        * hardware receive checksumming won't work.
+                        */
+                       if (likely(status >> 16 == (status & 0xffff))) {
+                               skb = sky2->rx_ring[sky2->rx_next].skb;
+                               skb->ip_summed = CHECKSUM_COMPLETE;
+                               skb->csum = status & 0xffff;
+                       } else {
+                               printk(KERN_NOTICE PFX "%s: hardware receive "
+                                      "checksum problem (status = %#x)\n",
+                                      dev->name, status);
+                               sky2->rx_csum = 0;
+                               sky2_write32(sky2->hw,
+                                            Q_ADDR(rxqaddr[le->link], Q_CSR),
+                                            BMU_DIS_RX_CHKSUM);
+                       }
                        break;
 
                case OP_TXINDEXLE: