Re: 5 bugs

[Bryce Harrington <bryce@canonical.com>]

On Thu, Jun 16, 2011 at 12:37:00PM +0100, Chris Wilson wrote:
> On Wed, 15 Jun 2011 18:10:29 -0700, Bryce Harrington <bryce@canonical.com> wrote:
> > Hi Max,
> > 
> > I currently am tracking 6 bug reports with the intel driver so far for
> > the oneiric development cycle, of which 5 have been forwarded upstream:
> > 
> >   https://bugs.freedesktop.org/show_bug.cgi?id=36515
> 
> This looks to be a continuation of the WAIT_EVENT on a dead pipe that we
> thought we had beaten into submission. The other reports provide more
> circumstantial evidence to suggest that the hang coincides with a hotplug
> event. I think the cause is a race between the kernel turning the pipe off
> due to the hotplug and reprobing and that uevent reaching the ddx. In the
> meantime, we've queued another video frame to execute on the dead pipe.
> Worse we may have queued it up long before the hotplug event and due to
> buffering in the GPU command stream it only gets executed afterwards.
> 
> commit 85345517fe6d4de27b0d6ca19fef9d28ac947c4a
> Author: Chris Wilson <chris@chris-wilson.co.uk>
> Date:   Sat Nov 13 09:49:11 2010 +0000
> 
>     drm/i915: Retire any pending operations on the old scanout when switching
> 
> Handles the case were we are changing modes. Unfortunately, disabling an
> output takes a different path. Though, I think we can a similar big hammer
> approach there are well.

As luck would have it, my own i965 laptop locked up today with I guess
this same bug.  IPEHR=0x01820000

Before I restart it, is there any data which could be gathered that
would assist you?

Otherwise, I can boot and test the patch you posted to the bug.

One of the difficulties with this type of bug is that it's so
intermittent and uncertain to reproduce (and so easily confused with
other unrelated freezes), that it's hard to tell for certain if a given
patch has definitively helped the situation.  Do you have suggestions on
ways of measuring this better, or techniques to help in triggering the
bug more reliably?

> >   https://bugs.freedesktop.org/show_bug.cgi?id=37393
> 
> Doesn't look to be the typical unresolved VGA on Arrandale failure.
> At first glance it suggests the misreporting of DPMS issue.
> 
> >   https://bugs.freedesktop.org/show_bug.cgi?id=37526
> 
> drm "hotplug" polling claims another victim. Daniel last volunteered to
> fix drm locking, which will help the general symptoms of a stall every
> 10s, but doesn't root cause the blanking.
> 
> >   https://bugs.freedesktop.org/show_bug.cgi?id=28798
> 
> I've fixed all the rendering issues I could find for sna. The best
> solution I can see to fix uxa is to remove the attempts to get it to use
> the 3D pipeline for core rendering routines.
> 
> >   https://bugs.freedesktop.org/show_bug.cgi?id=38191
> 
> Tiling artefacts, haven't investigated ff5 yet, so I've no idea where
> the issues lies or if it is a reoccurrence of a much older GM45 tiling
> bug under compiz.

Thanks.  Let me know if there are actions you need me to take on any of
these.

Bryce