From ed6445f5894dc5a952766725b0689451a58fcfd8 Mon Sep 17 00:00:00 2001 From: ChunTao Tso Date: Fri, 4 Aug 2023 14:57:44 +0800 Subject: [PATCH] drm/amd/display: set minimum of VBlank_nom [Why] If VBlank_nom is too small, it will cause VStartUP_Start smaller than VBackPorch + VSync width which is an invalid case for VStartUP_Start and where to send AS-SDP. [How] Setup a minimum value to VBlank_nom Reviewed-by: Reza Amini Acked-by: Wayne Lin Signed-off-by: ChunTao Tso Tested-by: Daniel Wheeler Signed-off-by: Alex Deucher --- .../amd/display/dc/dml/dcn314/dcn314_fpu.c | 21 ++++++++++++++++++- 1 file changed, 20 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/amd/display/dc/dml/dcn314/dcn314_fpu.c b/drivers/gpu/drm/amd/display/dc/dml/dcn314/dcn314_fpu.c index 07adb614366e..fb21572750e8 100644 --- a/drivers/gpu/drm/amd/display/dc/dml/dcn314/dcn314_fpu.c +++ b/drivers/gpu/drm/amd/display/dc/dml/dcn314/dcn314_fpu.c @@ -293,6 +293,17 @@ static unsigned int micro_sec_to_vert_lines(unsigned int num_us, struct dc_crtc_ return num_lines; } +static unsigned int get_vertical_back_porch(struct dc_crtc_timing *timing) +{ + unsigned int v_active = 0, v_blank = 0, v_back_porch = 0; + + v_active = timing->v_border_top + timing->v_addressable + timing->v_border_bottom; + v_blank = timing->v_total - v_active; + v_back_porch = v_blank - timing->v_front_porch - timing->v_sync_width; + + return v_back_porch; +} + int dcn314_populate_dml_pipes_from_context_fpu(struct dc *dc, struct dc_state *context, display_e2e_pipe_params_st *pipes, bool fast_validate) @@ -310,6 +321,7 @@ int dcn314_populate_dml_pipes_from_context_fpu(struct dc *dc, struct dc_state *c for (i = 0, pipe_cnt = 0; i < dc->res_pool->pipe_count; i++) { struct dc_crtc_timing *timing; unsigned int num_lines = 0; + unsigned int v_back_porch = 0; if (!res_ctx->pipe_ctx[i].stream) continue; @@ -323,9 +335,16 @@ int dcn314_populate_dml_pipes_from_context_fpu(struct dc *dc, struct dc_state *c else pipes[pipe_cnt].pipe.dest.vtotal = timing->v_total; + v_back_porch = get_vertical_back_porch(timing); + pipes[pipe_cnt].pipe.dest.vblank_nom = timing->v_total - pipes[pipe_cnt].pipe.dest.vactive; pipes[pipe_cnt].pipe.dest.vblank_nom = min(pipes[pipe_cnt].pipe.dest.vblank_nom, num_lines); - pipes[pipe_cnt].pipe.dest.vblank_nom = max(pipes[pipe_cnt].pipe.dest.vblank_nom, timing->v_sync_width); + // vblank_nom should not smaller than (VSync (timing->v_sync_width + v_back_porch) + 2) + // + 2 is because + // 1 -> VStartup_start should be 1 line before VSync + // 1 -> always reserve 1 line between start of vblank to vstartup signal + pipes[pipe_cnt].pipe.dest.vblank_nom = + max(pipes[pipe_cnt].pipe.dest.vblank_nom, timing->v_sync_width + v_back_porch + 2); pipes[pipe_cnt].pipe.dest.vblank_nom = min(pipes[pipe_cnt].pipe.dest.vblank_nom, max_allowed_vblank_nom); if (pipe->plane_state && -- 2.39.5