Re: [PATCH] drm/i915: Update PSR on resume.

[Daniel Vetter <daniel@ffwll.ch>]

On Mon, Aug 11, 2014 at 09:57:12AM -0700, Rodrigo Vivi wrote:
> Well, this fix the issue Linus faced.
> 
> Actually the issue I was aware of and trying to fix with this patch for a
> long time was reported by chromeos guys saying the psr wasn't propperly
> working after suspend/resume. They got the screen back but never got psr
> back again.
> 
> The original patch fix suspend/resume issues with psr and I decided to keep
> the same and subject for reference of what the problem this fixes and what
> was the patch history, but changed the place for the full setup to
> crtc_enable per your recommendation.

So if I read your patch correctly then we no do the initial psr setup in
crtc_enable, but only after driver load/resume. Before we do it always
when crtc_enable is called. That doesn't make sense. Also note that Linus
said it's also sometimes broken when using X normally.

Otoh if there's really something we need to in crtc_enable in addition to
what we do already, then we _must_ do it always. Otherwise runtime pm
(which is pretty much the same as system resume) will not work.
-Daniel

> 
> Thanks,
> Rodrigo.
> 
> 
> 
> On Sat, Aug 9, 2014 at 12:40 AM, Daniel Vetter <daniel.vetter@ffwll.ch>
> wrote:
> 
> > On Fri, Aug 8, 2014 at 7:19 PM, Rodrigo Vivi <rodrigo.vivi@intel.com>
> > wrote:
> > > From: Rodrigo Vivi <rodrigo.vivi@gmail.com>
> > >
> > > Some registers set during setup might not be persistent after
> > suspend/resume.
> > > This was causing bugs for some people that was unable to get PSR entry
> > state
> > > after resume cycle.
> > >
> > > v2: Adding some comments and better commit message explaining why this
> > is needed.
> > > v3: Getting back old setup_done variable and move from resume to
> > crtc_enable
> > >     as Daniel requested.
> > >
> > > Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
> > > Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
> >
> > I'm confused ... whats the use of this? Afaict that's exactly what the
> > code currently does.
> > -Daniel
> > --
> > Daniel Vetter
> > Software Engineer, Intel Corporation
> > +41 (0) 79 365 57 48 - http://blog.ffwll.ch
> >
> 
> 
> 
> -- 
> Rodrigo Vivi
> Blog: http://blog.vivi.eng.br

-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch