[PATCH] drm/msm/mdp5: expose "alpha" property

[Daniel Vetter]

On Mon, Oct 17, 2016 at 10:08:28AM -0400, Rob Clark wrote:
> On Mon, Oct 17, 2016 at 2:24 AM, Daniel Vetter <daniel at ffwll.ch> wrote:
> > On Fri, Oct 14, 2016 at 07:50:13PM -0400, Rob Clark wrote:
> >> We had this wired up already internally but initially did not expose the
> >> property pending bikeshed about alpha and color management properties.
> >> I noted that drm-hwc2 was looking for this property, and a couple other
> >> drivers already support it in the same way.  So time to expose it!
> >>
> >> Signed-off-by: Rob Clark <robdclark at gmail.com>
> >
> > Can we please have a bit of shared property setup in drm_blend.c and some
> > documentation how it is supposed to be used? Adding props is nice, but
> > greating an undocumented and ill-defined mess of them, not so much ;-)
> >
> > I'd prefer the full specced blending equation in the docs, including how
> > this interacts with fb formats which already have their own alpha value.
> 
> 
> It is used same way as rcar-du and atmel-hlcdc (and already is in
> kms-properties.csv
> 
> couldn't really tell you the blend equation.. but I guess it is
> "whatever android wants"

This is the kind of answer that uapi disasters are made of. Can you pls
figure this one out? Worst case just make it to fit msm ;-)

Also would be great to put the alpha value into drm_plane_state, like with
the other standardized properties.

Imo we really should be doing this right, and just because we didn't do it
right in the past isn't a good excuse.
-Daniel

> 
> BR,
> -R
> 
> > Thanks, Daniel
> >
> >> ---
> >>  drivers/gpu/drm/msm/mdp/mdp5/mdp5_plane.c | 3 +++
> >>  1 file changed, 3 insertions(+)
> >>
> >> diff --git a/drivers/gpu/drm/msm/mdp/mdp5/mdp5_plane.c b/drivers/gpu/drm/msm/mdp/mdp5/mdp5_plane.c
> >> index 432c098..b6f1fc66 100644
> >> --- a/drivers/gpu/drm/msm/mdp/mdp5/mdp5_plane.c
> >> +++ b/drivers/gpu/drm/msm/mdp/mdp5/mdp5_plane.c
> >> @@ -120,6 +120,7 @@ static void mdp5_plane_install_properties(struct drm_plane *plane,
> >>                               ARRAY_SIZE(name##_prop_enum_list))
> >>
> >>       INSTALL_RANGE_PROPERTY(zpos, ZPOS, 1, 255, 1);
> >> +     INSTALL_RANGE_PROPERTY(alpha, ALPHA, 0, 255, 255);
> >>
> >>       mdp5_plane_install_rotation_property(dev, plane);
> >>
> >> @@ -148,6 +149,7 @@ static int mdp5_plane_atomic_set_property(struct drm_plane *plane,
> >>       } while (0)
> >>
> >>       SET_PROPERTY(zpos, ZPOS, uint8_t);
> >> +     SET_PROPERTY(alpha, ALPHA, uint8_t);
> >>
> >>       dev_err(dev->dev, "Invalid property\n");
> >>       ret = -EINVAL;
> >> @@ -176,6 +178,7 @@ static int mdp5_plane_atomic_get_property(struct drm_plane *plane,
> >>       } while (0)
> >>
> >>       GET_PROPERTY(zpos, ZPOS, uint8_t);
> >> +     GET_PROPERTY(alpha, ALPHA, uint8_t);
> >>
> >>       dev_err(dev->dev, "Invalid property\n");
> >>       ret = -EINVAL;
> >> --
> >> 2.7.4
> >>
> >> _______________________________________________
> >> dri-devel mailing list
> >> dri-devel at lists.freedesktop.org
> >> https://lists.freedesktop.org/mailman/listinfo/dri-devel
> >
> > --
> > Daniel Vetter
> > Software Engineer, Intel Corporation
> > http://blog.ffwll.ch

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch