[PATCHv4 1/1] net: fec: fix regression on i.MX28 introduced by rx_copybreak support

[David Miller]

From: Fabio Estevam <festevam at gmail.com>
Date: Fri, 7 Nov 2014 10:26:15 -0200

> On Fri, Nov 7, 2014 at 7:02 AM, Lothar Waßmann <LW at karo-electronics.de> wrote:
>> commit 1b7bde6d659d ("net: fec: implement rx_copybreak to improve rx performance")
>> introduced a regression for i.MX28. The swap_buffer() function doing
>> the endian conversion of the received data on i.MX28 may access memory
>> beyond the actual packet size in the DMA buffer. fec_enet_copybreak()
>> does not copy those bytes, so that the last bytes of a packet may be
>> filled with invalid data after swapping.
>> This will likely lead to checksum errors on received packets.
>> E.g. when trying to mount an NFS rootfs:
>> UDP: bad checksum. From 192.168.1.225:111 to 192.168.100.73:44662 ulen 36
>>
>> Do the byte swapping and copying to the new skb in one go if
>> necessary.
>>
>> Signed-off-by: Lothar Waßmann <LW at KARO-electronics.de>
> 
> With this patch I am able to NFS mount on mx28 again. Thanks, Lothar!
> 
> Tested-by: Fabio Estevam <fabio.estevam at freescale.com>

Applied, thanks everyone.