Hi,
On Tue, 2018-07-17 at 22:41 +1000, Julian Calaby wrote:
Hi Paul,
On Tue, Jul 17, 2018 at 6:53 PM Paul Kocialkowski paul.kocialkowski@bootlin.com wrote:
Not all sunxi platforms with the first version of the Display Engine support an alpha component on the plane with the lowest z position (as in: lowest z-pos), that gets blended with the background color.
In particular, the A13 is known to have this limitation. However, it was recently discovered that the A20 and A33 are capable of having alpha on their lowest plane.
Thus, this introduces a specific quirk to indicate such support, per-platform. Since this was not tested on sun4i and sun6i platforms, a conservative approach is kept and this feature is not supported.
Signed-off-by: Paul Kocialkowski paul.kocialkowski@bootlin.com
drivers/gpu/drm/sun4i/sun4i_backend.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/sun4i/sun4i_backend.c b/drivers/gpu/drm/sun4i/sun4i_backend.c index a3cc398d4d80..cdc4a8a91ea2 100644 --- a/drivers/gpu/drm/sun4i/sun4i_backend.c +++ b/drivers/gpu/drm/sun4i/sun4i_backend.c @@ -584,8 +587,9 @@ static int sun4i_backend_atomic_check(struct sunxi_engine *engine, }
/* We can't have an alpha plane at the lowest position */
if (plane_states[0]->fb->format->has_alpha ||(plane_states[0]->alpha != DRM_BLEND_ALPHA_OPAQUE))
if ((plane_states[0]->fb->format->has_alpha ||(plane_states[0]->alpha != DRM_BLEND_ALPHA_OPAQUE)) &&!backend->quirks->supports_lowest_plane_alpha)From a readability perspective, it'd be fractionally nicer if the quirk check was before the alpha checks.
Agreed, I will do that in v2.
Thanks!