Re: [PATCH] drm/i915: Handle sync_seqno correctly when seqno has wrapped.

[Ben Widawsky <ben@bwidawsk.net>]

On Tue, 13 Nov 2012 17:45:14 +0100
Daniel Vetter <daniel@ffwll.ch> wrote:

> On Tue, Nov 13, 2012 at 5:39 PM, Ben Widawsky <ben@bwidawsk.net> wrote:
> >
> > Also as an overall comment, I want the patches to guarantee to catch
> > the bug you found, which I think with the randomness of
> > gem_stress - isn't. Specifically, we want the waiting ring to be
> > waiting on a pre-wrapped value. Maybe I missed that guarantee, but if
> > there is a quick/dirty way to make that happen, that would better than
> > running an arbitrary number of gem_stress tests.
> 
> I think running just gem_stress is ok - as long as the test has a
> reasonable good chance of blowing up. On future platforms something
> else than semaphores might blow up, or we might simply botch a seqno
> comparison. So imo having a test that just beats a bit on the
> systems+the wrap-around after each boot/resume should give us
> excellent coverage, and trying to engineer a perfect test for the
> single failure mode we now have in front of us might actually reduce
> coverage.
> -Daniel

I didn't say don't run gem_stress...

-- 
Ben Widawsky, Intel Open Source Technology Center