dect
/
linux-2.6
Archived
13
0
Fork 0
Code Releases Activity

davinci_emac: Do not free all rx dma descriptors during init 

This patch fixes a regression that was introduced by

commit 0a5f384677
davinci_emac: Add Carrier Link OK check in Davinci RX Handler

Said commit adds a check whether the carrier link is ok. If the link is
not ok, the skb is freed and no new dma descriptor added to the rx dma
channel. This causes trouble during initialization when the carrier
status has not yet been updated. If a lot of packets are received while
netif_carrier_ok returns false, all dma descriptors are freed and the
rx dma transfer is stopped.

The bug occurs when the board is connected to a network with lots of
traffic and the ifconfig down/up is done, e.g., when reconfiguring
the interface with DHCP.

The bug can be reproduced by flood pinging the davinci board while doing
ifconfig eth0 down
ifconfig eth0 up
on the board.

After that, the rx path stops working and the overrun value reported
by ifconfig is counting up.

This patch reverts commit 0a5f384677
and instead issues warnings only if cpdma_chan_submit returns -ENOMEM.

Signed-off-by: Christian Riesch <christian.riesch@omicron.at>
Cc: <stable@vger.kernel.org>
Cc: Hegde, Vinay <vinay.hegde@ti.com>
Cc: Cyril Chemparathy <cyril@ti.com>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Tested-by: Rajashekhara, Sudhakar <sudhakar.raj@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Christian Riesch 2012-02-23 01:14:17 +00:00 committed by David S. Miller
parent 1e0f03d57d
commit 5d69703263
1 changed files with 4 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
drivers/net/ethernet/ti/davinci_emac.c
View File

@ -1009,7 +1009,7 @@ static void emac_rx_handler(void *token, int len, int status)
int ret;
/* free and bail if we are shutting down */
if (unlikely(!netif_running(ndev) || !netif_carrier_ok(ndev))) {
if (unlikely(!netif_running(ndev))) {
dev_kfree_skb_any(skb);
return;
}
@ -1038,7 +1038,9 @@ static void emac_rx_handler(void *token, int len, int status)
recycle:
ret = cpdma_chan_submit(priv->rxchan, skb, skb->data,
skb_tailroom(skb), GFP_KERNEL);
if (WARN_ON(ret < 0))
WARN_ON(ret == -ENOMEM);
if (unlikely(ret < 0))
dev_kfree_skb_any(skb);
}