msm_fb: display: Add alpha enable check in blend

FIR and M/N scalar when used for downscaling, drops
alpha channel of the given layer. To notify this, alpha_drop flag
is updated accordingly. This flag need not be checked for layers
with no alpha plane. In some scenarios alpha_drop may get enabled
for the layers with no alpha plane and cause issues realted to blend
composition of layers. Check for setting alpha_drop only if source
ayer has alpha plane.

Change-Id: Ie64b30c045a78d0d68eb9efacc76902afae7850d
Signed-off-by: Mayank Chopra <makchopra@codeaurora.org>
This commit is contained in:
Mayank Chopra 2012-10-12 20:51:47 +05:30 committed by Stephen Boyd
parent 4ba4e55f0f
commit dca7ee656d

View file

@ -1932,6 +1932,7 @@ void mdp4_mixer_blend_setup(int mixer)
alpha_drop = 0; /* per stage */
/* alpha channel is lost on VG pipe when using QSEED or M/N */
if (s_pipe->pipe_type == OVERLAY_TYPE_VIDEO &&
s_pipe->alpha_enable &&
((s_pipe->op_mode & MDP4_OP_SCALEY_EN) ||
(s_pipe->op_mode & MDP4_OP_SCALEX_EN)) &&
!(s_pipe->op_mode & MDP4_OP_SCALEY_PIXEL_RPT))