[Intel-gfx] [PATCH] drm/i915: fix gpu hang vs. flip stall deadlocks

[Chris Wilson]

On Wed, Sep 04, 2013 at 12:12:49PM +0200, Daniel Vetter wrote:
> Since we've started to clean up pending flips when the gpu hangs in
> 
> commit 96a02917a0131e52efefde49c2784c0421d6c439
> Author: Ville Syrjälä <ville.syrjala at linux.intel.com>
> Date:   Mon Feb 18 19:08:49 2013 +0200
> 
>     drm/i915: Finish page flips and update primary planes after a GPU reset
> 
> the gpu reset work now also grabs modeset locks. But since since work
> items on our private work queue are not allowed to do that due to the
> flush_workqueue from the pageflip code this results in a neat
> deadlock:

I think QA have just hit this as well,

https://bugs.freedesktop.org/show_bug.cgi?id=68832

but since they conflated the real bug with an earlier report, I am going
to ask them to refile.
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre