Re: Excessive ethernet interrupts on AM335x board

Mark Jackson
2013-03-13T10:11:39Z

On 13/03/13 08:44, Koen Kooi wrote:
>
> Op 12 mrt. 2013, om 16:35 heeft Mark Jackson <mpfj-list@mimc.co.uk> het volgende geschreven:
>
>> I'm just fighting an issue with ethernet on our custom AM335x board:-
>>
>> # uname -a
>> Linux nanobone 3.9.0-rc2-00113-gd60f039 #139 Tue Mar 12 15:14:01 GMT 2013 armv7l GNU/Linux
>>
>> Every now and then, the whole unit slows to a crawl. The only indication of any problem is:-
>>
>> (a) the serial tty port becomes much less responsive
>> (b) normal ping times jump from 1ms to >10sec (sometimes >20sec !!)
>> (c) the ethernet interrupt count rockets (see below)
>
> You probably have PG2.x silicon, have a look at this patch: https://github.com/beagleboard/kernel/blob/3.8/patches/net/0003-cpsw-Fix-interrupt-storm-among-other-things.patch

No, it's 1.0 ...

[ 0.000000] Booting Linux on physical CPU 0x0
[ 0.000000] Linux version 3.9.0-rc2-00113-gd60f039-dirty (mpfj@mpfj-nanobone) (gcc version 4.5.4 (Buildroot 2012.11) ) #141 Wed Mar 13 09:14:03 GMT 2013
[ 0.000000] CPU: ARMv7 Processor [413fc082] revision 2 (ARMv7), cr=10c53c7d
[ 0.000000] CPU: PIPT / VIPT nonaliasing data cache, VIPT aliasing instruction cache
[ 0.000000] Machine: Generic AM33XX (Flattened Device Tree), model: Newflow AM335x NanoBone
[ 0.000000] Memory policy: ECC disabled, Data cache writeback
[ 0.000000] CPU: All CPU(s) started in SVC mode.
[ 0.000000] AM335X ES1.0 (neon )

The patch certainly didn't fix things (and possibly made things worse i.e. my nfs root kept dropping off even more).

> I saw some patches going into net-next today that might address this in a different way, but I haven't tried 3.9rc on an am335x yet.

I might track those down and test them.

Cheers
Mark J.