[Intel-gfx] [PATCH] drm/i915: preserve pipe A quirk in i9xx_set_pipeconf

[Daniel Vetter]

On Mon, Sep 23, 2013 at 10:17 AM, Ville Syrjälä
<ville.syrjala at linux.intel.com> wrote:
> Hmm. Why not just this?
>
> pipeconf = 0;
> if (pipe == PIPE_A && QUIRK)
>  pipeconf |= PIPECONF_ENABLE;

After resume the bios might or might not have enabled pipe A already.
We have a bit of magic to make sure that on resume we set up a decent
mode for pipe A, but I fear if I just smash pipe A to always on we'd
enable it in a bogus state and hang the hw. Hence the readback.

I think this should be part of the commit message ;-)
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch