Re: [PATCHv3 9/9] net: fec: fix regression on i.MX28 introduced by rx_copybreak support

From: Stefan Wahren
Date: Mon Nov 03 2014 - 17:58:37 EST


Hi Lothar,

> Lothar WaÃmann <LW@xxxxxxxxxxxxxxxxxxx> hat am 28. Oktober 2014 um 14:23
> geschrieben:
>
>
> 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

i think i experience the same problem with 3.18-rc2 on my mx28 board. I get
strange warnings about unexpected bytes from ping on my mx28 board and ping to
my mx28 board fails because of no response.

After applying the complete patch series these problems disappear. I'm looking
forward to see V4.

Thanks Stefan
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