From: Frank Li <Frank.Li@freescale.com>
Date: Tue, 7 May 2013 14:08:44 +0000 (+0000)
Subject: net: fec: fix kernel oops when plug/unplug cable many times
X-Git-Tag: v3.10-rc1~34^2~2
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=54309fa60b5f57b90c1842176f6045e665d21142;p=pandora-kernel.git

net: fec: fix kernel oops when plug/unplug cable many times

reproduce steps
 1. flood ping from other machine
 	ping -f -s 41000 IP
 2. run below script
    while [ 1 ]; do ethtool -s eth0 autoneg off;
    sleep 3;ethtool -s eth0 autoneg on; sleep 4; done;

You can see oops in one hour.

The reason is fec_restart clear BD but NAPI may use it.
The solution is disable NAPI and stop xmit when reset BD.
disable NAPI may sleep, so fec_restart can't be call in
atomic context.

Signed-off-by: Frank Li <Frank.Li@freescale.com>
Reviewed-by: Lucas Stach <l.stach@pengutronix.de>
Tested-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

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