On 2022-03-30 08:30, Rodrigo Siqueira Jordao wrote: > > > On 2022-03-29 16:18, Melissa Wen wrote: >> "Pre-multiplied" is the default pixel blend mode for KMS/DRM, as >> documented in supported_modes of drm_plane_create_blend_mode_property(): >> https://cgit.freedesktop.org/drm/drm-misc/tree/drivers/gpu/drm/drm_blend.c >> >> In this mode, both 'pixel alpha' and 'plane alpha' participate in the >> calculation, as described by the pixel blend mode formula in KMS/DRM >> documentation: >> >> out.rgb = plane_alpha * fg.rgb + >> (1 - (plane_alpha * fg.alpha)) * bg.rgb >> >> Considering the blend config mechanisms we have in the driver so far, >> the alpha mode that better fits this blend mode is the >> _PER_PIXEL_ALPHA_COMBINED_GLOBAL_GAIN, where the value for global_gain >> is the plane alpha (global_alpha). >> >> With this change, alpha property stops to be ignored. It also addresses >> Bug: https://gitlab.freedesktop.org/drm/amd/-/issues/1734 >> >> v2: >> * keep the 8-bit value for global_alpha_value (Nicholas) >> * correct the logical ordering for combined global gain (Nicholas) >> * apply to dcn10 too (Nicholas) >> >> Signed-off-by: Melissa Wen <mwen@xxxxxxxxxx> >> --- >> .../drm/amd/display/dc/dcn10/dcn10_hw_sequencer.c | 14 +++++++++----- >> drivers/gpu/drm/amd/display/dc/dcn20/dcn20_hwseq.c | 14 +++++++++----- >> 2 files changed, 18 insertions(+), 10 deletions(-) >> >> diff --git a/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_hw_sequencer.c b/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_hw_sequencer.c >> index ad757b59e00e..b1034e6258c8 100644 >> --- a/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_hw_sequencer.c >> +++ b/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_hw_sequencer.c >> @@ -2528,14 +2528,18 @@ void dcn10_update_mpcc(struct dc *dc, struct pipe_ctx *pipe_ctx) >> struct mpc *mpc = dc->res_pool->mpc; >> struct mpc_tree *mpc_tree_params = &(pipe_ctx->stream_res.opp->mpc_tree_params); >> - if (per_pixel_alpha) >> - blnd_cfg.alpha_mode = MPCC_ALPHA_BLEND_MODE_PER_PIXEL_ALPHA; >> - else >> - blnd_cfg.alpha_mode = MPCC_ALPHA_BLEND_MODE_GLOBAL_ALPHA; >> - >> blnd_cfg.overlap_only = false; >> blnd_cfg.global_gain = 0xff; >> + if (per_pixel_alpha && pipe_ctx->plane_state->global_alpha) { >> + blnd_cfg.alpha_mode = MPCC_ALPHA_BLEND_MODE_PER_PIXEL_ALPHA_COMBINED_GLOBAL_GAIN; >> + blnd_cfg.global_gain = pipe_ctx->plane_state->global_alpha_value; >> + } else if (per_pixel_alpha) { >> + blnd_cfg.alpha_mode = MPCC_ALPHA_BLEND_MODE_PER_PIXEL_ALPHA; >> + } else { >> + blnd_cfg.alpha_mode = MPCC_ALPHA_BLEND_MODE_GLOBAL_ALPHA; >> + } >> + >> if (pipe_ctx->plane_state->global_alpha) >> blnd_cfg.global_alpha = pipe_ctx->plane_state->global_alpha_value; >> else >> diff --git a/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_hwseq.c b/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_hwseq.c >> index 4290eaf11a04..b627c41713cc 100644 >> --- a/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_hwseq.c >> +++ b/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_hwseq.c >> @@ -2344,14 +2344,18 @@ void dcn20_update_mpcc(struct dc *dc, struct pipe_ctx *pipe_ctx) >> struct mpc *mpc = dc->res_pool->mpc; >> struct mpc_tree *mpc_tree_params = &(pipe_ctx->stream_res.opp->mpc_tree_params); >> - if (per_pixel_alpha) >> - blnd_cfg.alpha_mode = MPCC_ALPHA_BLEND_MODE_PER_PIXEL_ALPHA; >> - else >> - blnd_cfg.alpha_mode = MPCC_ALPHA_BLEND_MODE_GLOBAL_ALPHA; >> - >> blnd_cfg.overlap_only = false; >> blnd_cfg.global_gain = 0xff; >> + if (per_pixel_alpha && pipe_ctx->plane_state->global_alpha) { >> + blnd_cfg.alpha_mode = MPCC_ALPHA_BLEND_MODE_PER_PIXEL_ALPHA_COMBINED_GLOBAL_GAIN; >> + blnd_cfg.global_gain = pipe_ctx->plane_state->global_alpha_value; >> + } else if (per_pixel_alpha) { >> + blnd_cfg.alpha_mode = MPCC_ALPHA_BLEND_MODE_PER_PIXEL_ALPHA; >> + } else { >> + blnd_cfg.alpha_mode = MPCC_ALPHA_BLEND_MODE_GLOBAL_ALPHA; >> + } >> + > > Hi Melissa, > > Thanks a lot for this patch. I run your patch in our CI, and everything looks good from the IGT test result. > > In this sense: > Tested-by: Rodrigo Siqueira <Rodrigo.Siqueira@xxxxxxx> > > However, I think it is still necessary to have someone else review. > > Harry, Nick, or Zhan, what do you think about this change? > Looks good to me. Reviewed-by: Harry Wentland <harry.wentland@xxxxxxx> Harry > Thanks > Siqueira > >> if (pipe_ctx->plane_state->global_alpha) >> blnd_cfg.global_alpha = pipe_ctx->plane_state->global_alpha_value; >> else >
