From 7dd56b4aa2b64948d430dfd3e3b6295e8cfabaa8 Mon Sep 17 00:00:00 2001 From: Nicholas Kazlauskas Date: Wed, 19 Aug 2020 13:37:54 -0400 Subject: [PATCH] drm/amd/display: Reject overlay plane configurations in multi-display scenarios [Why] These aren't stable on some platform configurations when driving multiple displays, especially on higher resolution. In particular the delay in asserting p-state and validating from x86 outweights any power or performance benefit from the hardware composition. Under some configurations this will manifest itself as extreme stutter or unresponsiveness especially when combined with cursor movement. [How] Disable these for now. Exposing overlays to userspace doesn't guarantee that they'll be able to use them in any and all configurations and it's part of the DRM contract to have userspace gracefully handle validation failures when they occur. Valdiation occurs as part of DC and this in particular affects RV, so disable this in dcn10_global_validation. Signed-off-by: Nicholas Kazlauskas Reviewed-by: Hersen Wu --- drivers/gpu/drm/amd/display/dc/dcn10/dcn10_resource.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_resource.c b/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_resource.c index 1a83b8f589d46..c2af208b81eb4 100644 --- a/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_resource.c +++ b/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_resource.c @@ -1215,6 +1215,7 @@ static enum dc_status dcn10_validate_global(struct dc *dc, struct dc_state *cont bool video_large = false; bool desktop_large = false; bool dcc_disabled = false; + bool mpo_enabled = false; for (i = 0; i < context->stream_count; i++) { if (context->stream_status[i].plane_count == 0) @@ -1223,6 +1224,9 @@ static enum dc_status dcn10_validate_global(struct dc *dc, struct dc_state *cont if (context->stream_status[i].plane_count > 2) return DC_FAIL_UNSUPPORTED_1; + if (context->stream_status[i].plane_count > 1) + mpo_enabled = true; + for (j = 0; j < context->stream_status[i].plane_count; j++) { struct dc_plane_state *plane = context->stream_status[i].plane_states[j]; @@ -1246,6 +1250,10 @@ static enum dc_status dcn10_validate_global(struct dc *dc, struct dc_state *cont } } + /* Disable MPO in multi-display configurations. */ + if (context->stream_count > 1 && mpo_enabled) + return DC_FAIL_UNSUPPORTED_1; + /* * Workaround: On DCN10 there is UMC issue that causes underflow when * playing 4k video on 4k desktop with video downscaled and single channel