Android Hardware Composer supports alpha values applied to layers. Enabling non-opaque layers for the STM CRTC could help offload GPU resources for screen composition.
Signed-off-by: Raphael Gallais-Pou raphael.gallais-pou@foss.st.com Acked-by: Yannick Fertre yannick.fertre@foss.st.com Reviewed-by: Yannick Fertre yannick.fertre@foss.st.com --- drivers/gpu/drm/stm/ltdc.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/stm/ltdc.c b/drivers/gpu/drm/stm/ltdc.c index 195de30eb90c..e0fef8bacfa8 100644 --- a/drivers/gpu/drm/stm/ltdc.c +++ b/drivers/gpu/drm/stm/ltdc.c @@ -845,7 +845,7 @@ static void ltdc_plane_atomic_update(struct drm_plane *plane, LXCFBLR_CFBLL | LXCFBLR_CFBP, val);
/* Specifies the constant alpha value */ - val = CONSTA_MAX; + val = newstate->alpha >> 8; reg_update_bits(ldev->regs, LTDC_L1CACR + lofs, LXCACR_CONSTA, val);
/* Specifies the blending factors */ @@ -997,6 +997,8 @@ static struct drm_plane *ltdc_plane_create(struct drm_device *ddev,
drm_plane_helper_add(plane, <dc_plane_helper_funcs);
+ drm_plane_create_alpha_property(plane); + DRM_DEBUG_DRIVER("plane:%d created\n", plane->base.id);
return plane;