Re: [forcedeth bug] Re: [GIT] Networking

Ingo Molnar
2011-08-05T10:29:03Z

* Jiri Pirko <jpirko@redhat.com> wrote:

> Thu, Aug 04, 2011 at 11:53:54PM CEST, mingo@elte.hu wrote:
> >
> >* Ingo Molnar <mingo@elte.hu> wrote:
> >
> >> 0891b0e08937: forcedeth: fix vlans
> >
> >Hm, forcedeth is still giving me trouble even on latest -git that has
> >the above fix included.
> >
> >The symptom is a stuck interface, no packets in. There's a frame
> >error RX packet:
> >
> > [root@mercury ~]# ifconfig eth0
> > eth0 Link encap:Ethernet HWaddr 00:13:D4:DC:41:12
> > inet addr:10.0.1.13 Bcast:10.0.1.255 Mask:255.255.255.0
> > UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
> > RX packets:0 errors:1 dropped:0 overruns:0 frame:1
> > TX packets:531 errors:0 dropped:0 overruns:0 carrier:0
> > collisions:0 txqueuelen:1000
> > RX bytes:0 (0.0 b) TX bytes:34112 (33.3 KiB)
> > Interrupt:35
> >
> >Weirdly enough a defconfig x86 bootup works just fine - it's certain
> >.config combinations that trigger the bug. I've attached such a
> >config.
> >
> >Note that at least once i've observed a seemingly good kernel going
> >'bad' after a couple of minutes uptime. I've also observed
> >intermittent behavior - apparent lost packets and a laggy network.
> >
> >I have done 3 failed attempts to bisect it any further - i got to the
> >commit that got fixed by:
> >
> > 0891b0e08937: forcedeth: fix vlans
> >
> >... but that's something we already knew.
> >
> >Let me know if there's any data i can provide to help debug this
> >problem.
> >
> >Thanks,
> >
> > Ingo
>
> Interesting.
>
> Is DEV_HAS_VLAN set in id->driver_data (L5344) ?

How do i tell that without hacking the driver?

> If so, would you try to disable both rx an tx vlan accel using
> ethtool and see if it helps?

Should i do that when the device is in a stuck state and see whether
it recovers?

Also, please provide the exact ethtool command sequences i should
try, this makes it easier for me to test exactly what you want me to
test.

Thanks,

Ingo