When global alpha is enabled, per-pixel alpha is ignored. Allow userspace to explicitly specify whether to use per-pixel alpha by exposing it through the blend mode property. The reference manual doesn't say whether the per-pixel alpha is pre-multiplied or not, but Anatoliy created a test case that shows alpha is not pre-multiplied [1]. By default alpha is disabled, since this matches the behavior before this patch.
[1] https://lore.kernel.org/dri-devel/mw4pr12mb7165cddb17cf0855ea19aacde6...@mw4pr12mb7165.namprd12.prod.outlook.com/ Signed-off-by: Sean Anderson <[email protected]> --- Changes in v2: - Advertise coverage instead of premulti, since that's what the hardware supports. - Set default blend mode to none since that's what the default was before this series. drivers/gpu/drm/xlnx/zynqmp_kms.c | 35 ++++++++++++++++++++++++++++--- 1 file changed, 32 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/xlnx/zynqmp_kms.c b/drivers/gpu/drm/xlnx/zynqmp_kms.c index 284acb23c53e..aadba00921c1 100644 --- a/drivers/gpu/drm/xlnx/zynqmp_kms.c +++ b/drivers/gpu/drm/xlnx/zynqmp_kms.c @@ -62,6 +62,13 @@ static int zynqmp_dpsub_plane_atomic_check(struct drm_plane *plane, if (!new_plane_state->crtc) return 0; + if (new_plane_state->pixel_blend_mode != DRM_MODE_BLEND_PIXEL_NONE && + new_plane_state->alpha >> 8 != 0xff) { + drm_dbg_kms(plane->dev, + "Plane alpha must be 1.0 when using pixel alpha\n"); + return -EINVAL; + } + crtc_state = drm_atomic_get_crtc_state(state, new_plane_state->crtc); if (IS_ERR(crtc_state)) return PTR_ERR(crtc_state); @@ -118,9 +125,13 @@ static void zynqmp_dpsub_plane_atomic_update(struct drm_plane *plane, zynqmp_disp_layer_update(layer, new_state); - if (plane->index == ZYNQMP_DPSUB_LAYER_GFX) - zynqmp_disp_blend_set_global_alpha(dpsub->disp, true, + if (plane->index == ZYNQMP_DPSUB_LAYER_GFX) { + bool blend = plane->state->pixel_blend_mode == + DRM_MODE_BLEND_PIXEL_NONE; + + zynqmp_disp_blend_set_global_alpha(dpsub->disp, blend, plane->state->alpha >> 8); + } /* * Unconditionally enable the layer, as it may have been disabled @@ -137,11 +148,18 @@ static const struct drm_plane_helper_funcs zynqmp_dpsub_plane_helper_funcs = { .atomic_disable = zynqmp_dpsub_plane_atomic_disable, }; +void zynqmp_dpsub_plane_atomic_reset(struct drm_plane *plane) +{ + drm_atomic_helper_plane_reset(plane); + if (plane->state) + plane->state->pixel_blend_mode = DRM_MODE_BLEND_PIXEL_NONE; +} + static const struct drm_plane_funcs zynqmp_dpsub_plane_funcs = { .update_plane = drm_atomic_helper_update_plane, .disable_plane = drm_atomic_helper_disable_plane, .destroy = drm_plane_cleanup, - .reset = drm_atomic_helper_plane_reset, + .reset = zynqmp_dpsub_plane_atomic_reset, .atomic_duplicate_state = drm_atomic_helper_plane_duplicate_state, .atomic_destroy_state = drm_atomic_helper_plane_destroy_state, }; @@ -180,9 +198,20 @@ static int zynqmp_dpsub_create_planes(struct zynqmp_dpsub *dpsub) return ret; if (i == ZYNQMP_DPSUB_LAYER_GFX) { + unsigned int blend_modes = + BIT(DRM_MODE_BLEND_PIXEL_NONE) | + BIT(DRM_MODE_BLEND_COVERAGE); + unsigned int def = DRM_MODE_BLEND_COVERAGE; + ret = drm_plane_create_alpha_property(plane); if (ret) return ret; + + ret = drm_plane_create_blend_mode_default(plane, + blend_modes, + def); + if (ret) + return ret; } } -- 2.35.1.1320.gc452695387.dirty
