From: Stephen Hemminger <shemminger@linux-foundation.org>
To: Jeff Garzik <jgarzik@pobox.com>
Cc: netdev@vger.kernel.org
Subject: [PATCH] sky2: turn off Rx checksum on bad hardware
Date: Thu, 8 Mar 2007 12:42:30 -0800 [thread overview]
Message-ID: <20070308124230.208b7c9a@freekitty> (raw)
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>
---
drivers/net/sky2.c | 24 +++++++++++++++++++++---
1 file changed, 21 insertions(+), 3 deletions(-)
--- sky2-dev.orig/drivers/net/sky2.c 2007-03-05 16:49:31.000000000 -0800
+++ sky2-dev/drivers/net/sky2.c 2007-03-05 16:49:45.000000000 -0800
@@ -2165,9 +2165,27 @@
/* 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:
next reply other threads:[~2007-03-08 20:45 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-03-08 20:42 Stephen Hemminger [this message]
2007-03-09 16:52 ` [PATCH] sky2: turn off Rx checksum on bad hardware Jeff Garzik
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