From 3b6df06f01cdbff3b610b492ad4879691afdc70d Mon Sep 17 00:00:00 2001 From: Wesley Chalmers Date: Wed, 31 May 2023 13:29:34 -0400 Subject: [PATCH] drm/amd/display: Block optimize on consecutive FAMS enables [WHY] It is possible to commit state multiple times in rapid succession with FAMS enabled; if each of these commits were to set optimized_required, then the user may see latency. [HOW] fw_based_mclk_switching is currently not used in dc->clk_mgr; use it to track whether the current state has FAMS enabled; if it has, then do not disable FAMS in prepare_bandwidth, and do not set optimized_required. Reviewed-by: Rodrigo Siqueira Signed-off-by: Wesley Chalmers Tested-by: Daniel Wheeler Signed-off-by: Alex Deucher Acked-by: Hamza Mahfooz Signed-off-by: Alex Deucher --- drivers/gpu/drm/amd/display/dc/dcn20/dcn20_hwseq.c | 3 +++ drivers/gpu/drm/amd/display/dc/dcn30/dcn30_hwseq.c | 22 +++++++++++++++++++--- 2 files changed, 22 insertions(+), 3 deletions(-) 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 dba7eab..5cfa378 100644 --- a/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_hwseq.c +++ b/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_hwseq.c @@ -2127,6 +2127,9 @@ void dcn20_optimize_bandwidth( dc_dmub_srv_p_state_delegate(dc, true, context); context->bw_ctx.bw.dcn.clk.p_state_change_support = true; + dc->clk_mgr->clks.fw_based_mclk_switching = true; + } else { + dc->clk_mgr->clks.fw_based_mclk_switching = false; } dc->clk_mgr->funcs->update_clocks( diff --git a/drivers/gpu/drm/amd/display/dc/dcn30/dcn30_hwseq.c b/drivers/gpu/drm/amd/display/dc/dcn30/dcn30_hwseq.c index 7d38977..4cd4ae0 100644 --- a/drivers/gpu/drm/amd/display/dc/dcn30/dcn30_hwseq.c +++ b/drivers/gpu/drm/amd/display/dc/dcn30/dcn30_hwseq.c @@ -949,9 +949,13 @@ void dcn30_set_disp_pattern_generator(const struct dc *dc, } void dcn30_prepare_bandwidth(struct dc *dc, - struct dc_state *context) + struct dc_state *context) { - if (context->bw_ctx.bw.dcn.clk.fw_based_mclk_switching) { + bool p_state_change_support = context->bw_ctx.bw.dcn.clk.p_state_change_support; + /* Any transition into an FPO config should disable MCLK switching first to avoid + * driver and FW P-State synchronization issues. + */ + if (context->bw_ctx.bw.dcn.clk.fw_based_mclk_switching || dc->clk_mgr->clks.fw_based_mclk_switching) { dc->optimized_required = true; context->bw_ctx.bw.dcn.clk.p_state_change_support = false; } @@ -962,7 +966,19 @@ void dcn30_prepare_bandwidth(struct dc *dc, dc->clk_mgr->funcs->set_max_memclk(dc->clk_mgr, dc->clk_mgr->bw_params->clk_table.entries[dc->clk_mgr->bw_params->clk_table.num_entries - 1].memclk_mhz); dcn20_prepare_bandwidth(dc, context); + /* + * enabled -> enabled: do not disable + * enabled -> disabled: disable + * disabled -> enabled: don't care + * disabled -> disabled: don't care + */ + if (!context->bw_ctx.bw.dcn.clk.fw_based_mclk_switching) + dc_dmub_srv_p_state_delegate(dc, false, context); - dc_dmub_srv_p_state_delegate(dc, false, context); + if (context->bw_ctx.bw.dcn.clk.fw_based_mclk_switching || dc->clk_mgr->clks.fw_based_mclk_switching) { + /* After disabling P-State, restore the original value to ensure we get the correct P-State + * on the next optimize. */ + context->bw_ctx.bw.dcn.clk.p_state_change_support = p_state_change_support; + } } -- 2.7.4