Subject: Re: [PATCH v2 3/3] ucc_geth: Fix hangs after switching from full to half duplex

From: Anton Vorontsov <[email-masked]>
Date: Fri, 11 Sep 2009 01:09:36 +0400

On Thu, Sep 10, 2009 at 11:40:53PM +0400, Anton Vorontsov wrote:
> On Thu, Sep 10, 2009 at 01:04:32PM -0500, Scott Wood wrote:
> > Anton Vorontsov wrote:
> > >MPC8360 QE UCC ethernet controllers hang when changing link duplex
> > >under a load (a bit of NFS activity is enough).
> > >
> > >  PHY: mdio@e0102120:00 - Link is Up - 1000/Full
> > >  sh-3.00# ethtool -s eth0 speed 100 duplex half autoneg off
> > >  PHY: mdio@e0102120:00 - Link is Down
> > >  PHY: mdio@e0102120:00 - Link is Up - 100/Half
> > >  NETDEV WATCHDOG: eth0 (ucc_geth): transmit queue 0 timed out
> > >  ------------[ cut here ]------------
> > >  Badness at c01fcbd0 [verbose debug info unavailable]
> > >  NIP: c01fcbd0 LR: c01fcbd0 CTR: c0194e44
> > >  ...
> > >
> > >The cure is to disable the controller before changing speed/duplex
> > >and enable it afterwards.
> > >
> > >Since ugeth_graceful_stop_{tx,rx} now may be called from an atomic
> > >context, switch the two functions from msleep() to mdelay().
> > 
> > Ouch.
> 
> Yeah, right... delaying for 10ms with irqs off isn't good.
> 
> > Can we put this in a workqueue or something?
> 
> adjust_link() itself isn't called from an atomic context.

Oops. I though that phylib calls us from a workqueue, not a timer. Hm...

Will be a little bit more work..

-- 
Anton Vorontsov
email: [email-masked]
irc://irc.freenode.net/bd2