Re: [PATCH 2/3] drm/i915: add destination color key support

[Jesse Barnes <jbarnes@virtuousgeek.org>]

On Wed, 16 Nov 2011 17:10:53 +0100
Daniel Vetter <daniel@ffwll.ch> wrote:

> On Mon, Nov 14, 2011 at 21:22, Jesse Barnes <jbarnes@virtuousgeek.org> wrote:
> > Add new ioctls for getting and setting the current destination color
> > key.  This allows for simple overlay display control by matching a color
> > key value in the primary plane before blending the overlay on top.
> >
> > Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
> 
> Just a few comments because reviewing patches here is a royal pain:
> - Is taking dev->struct_mutex really required around the register access?

Oh did I leave them in place for these paths?  I'll drop them too.

> - You unconditionally enable the color key. Do we anticipate any other
> uses (like no color key or dst color key) or is this just the
> make-Xv-work ioctl?

I was thinking of that...  W/o a src or dest key, the overlay will
always be on top.  That's probably reasonable for simple cases, so
having a "key present" flag makes sense.

Which means setting a 0 dest key would mean "disable dest key" and go
back to the default behavior.  So the interface would stay the same
even if we added other key types in the future.

-- 
Jesse Barnes, Intel Open Source Technology Center