Re: [PATCH] drm/i915: preserve pipe A quirk in i9xx_set_pipeconf

[Daniel Vetter <daniel@ffwll.ch>]

On Mon, Sep 23, 2013 at 10:55:35AM +0100, Chris Wilson wrote:
> On Mon, Sep 23, 2013 at 10:37:02AM +0200, Daniel Vetter wrote:
> > On Mon, Sep 23, 2013 at 10:17 AM, Ville Syrjälä
> > <ville.syrjala@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.
> 
> Yet, the
> 
> if (A)
>   pipeconf = READ() & MAGIC;
> else
>   pipeconf = 0;
> if (B)
>   pipeconf = READ() & MAGIC2;

I don't see that 2nd READ() you're seeing ... Where is it?
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch