Re: [PATCH 2.6.30-rc4] r8169: avoid losing MSI interrupts

[David Dillow <dave@thedillows.org>]

On Sun, 2009-05-24 at 23:15 +0200, Francois Romieu wrote:
> David Dillow <dave@thedillows.org> :
> [...]
> > This fixes the lockups I've seen. Both MSI and level-triggered interrupt
> > configurations survive over an hour of testing when it would lockup in
> > under 90 seconds before. I am certain of the analysis of the root cause,
> > but there may be better ways to fix it. There may also be a theoretical
> > race window between the ending of a NAPI poll cycle and a link change
> > interrupt coming in, but I'm not sure it would matter. 
> 
> It makes sense.
> 
> If I understand correctly, one should expect to find some pending Tx
> event in the ISR of a failed card when reading the registers with
> ethtool.
> 
> Has someone noticed it ?

Yes, that's part of how I came to this conclusion, I put a debug patch
together that looked at the IRQ status 2 seconds after the last IRQ came
in. Then I waited for the chip to lock and the timer to fire. It showed
0x0085 in the IntrStatus register.

I didn't know I could do that with ethtool, but that would've been a
nice way to go, too. :)