Re: [PATCH] drm/i915: Suppress hotplug work during PM suspend/resume

[Chris Wilson <chris@chris-wilson.co.uk>]

On Thu, 10 May 2012 11:39:49 +0200, Takashi Iwai <tiwai@suse.de> wrote:
> At Thu, 10 May 2012 10:25:44 +0100,
> Chris Wilson wrote:
> > 
> > On Thu, 10 May 2012 11:19:11 +0200, Takashi Iwai <tiwai@suse.de> wrote:
> > > At Thu, 10 May 2012 11:06:46 +0200,
> > > Daniel Vetter wrote:
> > > > This patch is not just for hotplug, but for all the delayed work and timer
> > > > stuff the driver does. And we _do_ have a bug report that leaking the rps
> > > > work (for snb+ turbo mode) across either a s/r cycle or a gpu reset kills
> > > > the driver.
> > > 
> > > Yes, but my point is that Chris's patch (at least the commit above
> > > alone) won't fix the problem we faced.
> > 
> > The patch I thought you two were talking about was:
> > http://cgit.freedesktop.org/~ickle/linux-2.6/commit/?h=fastboot&id=a5f91dcc3cb7a9dc1214d5014ea6f0338824ad8e
> > which is what I thought we had planned to fix the residual issue.
> 
> Thanks, this explains better :)
> 
> But, as far as I checked, the hotplug event wasn't a leftover but
> newly triggered during the resume procedure.  Thus there is still a
> race even with the patch [drm/i915: Cancel outstanding modeset workers
> before suspend].

Which should be fixed with Adam's patch to only restore IRQs after doing
the modeset upon resume; if I am following all the threads of this bug
correctly.
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre