tree 3081935967a753fff95552ff4c47f552a26e362f
parent 1e0f03d57d7092f1f4d93a91fb7ece57b1514a88
author Christian Riesch <christian.riesch@omicron.at> 1329959657 +0000
committer David S. Miller <davem@davemloft.net> 1330071910 -0500

davinci_emac: Do not free all rx dma descriptors during init

This patch fixes a regression that was introduced by

commit 0a5f38467765ee15478db90d81e40c269c8dda20
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 0a5f38467765ee15478db90d81e40c269c8dda20
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>