Re: [Intel-gfx] [PATCH] drm/i915: Quirk the pipe A quirk in the modeset state checker

[Daniel Vetter <daniel@ffwll.ch>]

On Wed, May 29, 2013 at 10:06:20AM +0100, Chris Wilson wrote:
> On Wed, May 29, 2013 at 10:41:29AM +0200, Daniel Vetter wrote:
> > If we always force the pipe A to on we can't use the hw state to
> > decide whether it should be on. Hence quirk the quirk.
> > 
> > The problem is that crtc->active tracks the state of the entire
> > display pipe, i.e. including planes, encoders and all. But our hw
> > state readout simply looks at the pipe. But with the pipe A quirk we
> > force-enable that (together with it's pll). To fix that mismatch we
> > have two options:
> > - Quirk the checked state to match what our sw tracking states if the
> >   pipe A quirk is in effect.
> > - Improve the hw state readout to not get fooled by the pipe A quirk.
> > 
> > Since we already have similar state clamping in e.g. assert_pipe I've
> > opted for the first variant. Also note that we don't really loose any
> > state checking: Individual pieces of the abstract crtc pipe are
> > checked in the enable/disable functions with the various asssert_*
> > checks we have, and the hw state check code doesn't check anything if
> > the pipe is off anyway.
> > 
> > v2: Pimp commit message after discussion with Chris and only apply the
> > quirk for the quirk if we're checking pipe A. Otherwise we'll miss
> > state checking for pipe B on i830M ...
> > 
> > v3: Make the code comment consistent with the improved commit message,
> > too (Chris).
> > 
> > Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=64764
> > Cc: stable@vger.kernel.org
> > Cc: Chris Wilson <chris@chris-wilson.co.uk>
> > Reported-and-Tested-by: mlsemon35@gmail.com (v1)
> > Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
> Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>

Picked up for -fixes, thanks for the review.
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch