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

[Daniel Vetter]

On Wed, May 29, 2013 at 9:54 AM, Chris Wilson <chris at chris-wilson.co.uk> wrote:
> On Wed, May 29, 2013 at 09:28:22AM +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.
>
> This is misleading as it is not the hw state that is unreliable, but
> crtc->active that is a misnomer. The quirk makes the hw state
> inconsistent with the bookkeeping.

Well, crtc->active tracks much more than what we quirk, it means that
the entire display pipe is on (including encoders, planes and all) and
pumping pixels. The quirk only keeps pipe&pll running though. I've
seen two options:
- this one here
- pimping the get_config stuff to figure out we're quirked and e.g.
check whether the plane is running.

Clamping the tracked state seemed to be the quicker option, and we
already have similar (in spirit) hacks in assert_pipe.

Also, we shouldn't lose any assert coverage with this: The pipe
enabled state is independently asserted in the enable/disable
functions and the hw state doesn't really check anything if the pipe
is logically off.
-Daniel
--
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch