net: mv643xx: interface does not transmit after some time

[Ezequiel Garcia]

(let's expand the Cc a bit)

On 10 February 2016 at 19:57, Andrew Lunn <andrew at lunn.ch> wrote:
> On Wed, Feb 10, 2016 at 07:40:54PM +0100, Thomas Schlöter wrote:
>>
>> > Am 08.02.2016 um 19:49 schrieb Thomas Schlöter <thomas at schloeter.net>:
>> >
>> >
>> >> Am 07.02.2016 um 22:07 schrieb Thomas Schlöter <thomas at schloeter.net>:
>> >>
>> >> Am 07.02.2016 um 21:35 schrieb Andrew Lunn <andrew at lunn.ch>:
>> >>>
>> >>>>> FWIW, we had a similar bug report in Debian recently:
>> >>>>> https://lists.debian.org/debian-arm/2016/01/msg00098.html
>> >>>
>> >>> Hi Thomas
>> >>>
>> >>> I this thread, Ian Campbell mentions a patch. Please could you try
>> >>> that patch and see if it fixes your problem.
>> >>>
>> >>> Thanks
>> >>>   Andrew
>> >>
>> >> Hi Andrew,
>> >>
>> >> I just applied the patch and the NAS is now running it. I???ll try to crash it tonight and keep you informed whether it worked.
>> >>
>> >> Thanks
>> >>    Thomas
>> >
>> > Hi Andrew,
>> >
>> > the patch did not fix the problem. After 1.2 GiB RX and 950 MiB TX, the interface crashed again.
>> >
>> > Now I switched off RX/TX offload just to make sure we are talking about the same problem. If we are, the interface should be stable without offload, right?
>> >
>> >     Thomas
>>
>> Okay, so I have installed ethtool and switched off all offload features available. Now the NAS is running rock solid for two days. I backed up my Mac using Time Machine / netatalk (450 GiB transferred) and some Linux machines via NFS (100 GiB total) without a problem.
>>
>> How much code is used for mv643xx offload functionality?
>> Is it possible to debug things in the driver and figure out what happens during the crash?
>> Is the hardware offload interface proprietary or reverse engineered or is it a well known API that can be analyzed?
>
> Hi Thomas
>
> Ezequiel Garcia probably knows this part of the driver and hardware
> the best...
>

The TCP segmentation offload (TSO) implemented in this driver is
mostly a software thing.

I'm CCing Karl and Philipp, who have fixed subtle issues in the TSO
path, and may be able to help figure this one out.

-- 
Ezequiel García, VanguardiaSur
www.vanguardiasur.com.ar