This is a note to let you know that I've just added the patch titled drm/amd/display: Screen corruption on dual displays (DP+USB-C) to the 5.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: drm-amd-display-screen-corruption-on-dual-displays-d.patch and it can be found in the queue-5.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 59c9dccf31e1550972cc64a6adb97c928208c1c8 Author: Qingqing Zhuo <qingqing.zhuo@xxxxxxx> Date: Thu Jul 30 15:35:41 2020 -0400 drm/amd/display: Screen corruption on dual displays (DP+USB-C) [ Upstream commit ce271b40a91f781af3dee985c39e841ac5148766 ] [why] Current pipe merge and split logic only supports cases where new dc_state is allocated and relies on dc->current_state to gather information from previous dc_state. Calls to validate_bandwidth on UPDATE_TYPE_MED would cause an issue because there is no new dc_state allocated, and data in dc->current_state would be overwritten during pipe merge. [how] Only allow validate_bandwidth when new dc_state space is created. Signed-off-by: Qingqing Zhuo <qingqing.zhuo@xxxxxxx> Reviewed-by: Nicholas Kazlauskas <Nicholas.Kazlauskas@xxxxxxx> Acked-by: Rodrigo Siqueira <Rodrigo.Siqueira@xxxxxxx> Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/gpu/drm/amd/display/dc/core/dc.c b/drivers/gpu/drm/amd/display/dc/core/dc.c index 92eb1ca1634fc..22cbfda6ab338 100644 --- a/drivers/gpu/drm/amd/display/dc/core/dc.c +++ b/drivers/gpu/drm/amd/display/dc/core/dc.c @@ -2621,7 +2621,7 @@ void dc_commit_updates_for_stream(struct dc *dc, copy_stream_update_to_stream(dc, context, stream, stream_update); - if (update_type > UPDATE_TYPE_FAST) { + if (update_type >= UPDATE_TYPE_FULL) { if (!dc->res_pool->funcs->validate_bandwidth(dc, context, false)) { DC_ERROR("Mode validation failed for stream update!\n"); dc_release_state(context); diff --git a/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_resource.c b/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_resource.c index f31f48dd0da29..aaf9a99f9f045 100644 --- a/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_resource.c +++ b/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_resource.c @@ -3209,6 +3209,9 @@ static noinline bool dcn20_validate_bandwidth_fp(struct dc *dc, context->bw_ctx.dml.soc.allow_dram_clock_one_display_vactive = dc->debug.enable_dram_clock_change_one_display_vactive; + /*Unsafe due to current pipe merge and split logic*/ + ASSERT(context != dc->current_state); + if (fast_validate) { return dcn20_validate_bandwidth_internal(dc, context, true); } diff --git a/drivers/gpu/drm/amd/display/dc/dcn21/dcn21_resource.c b/drivers/gpu/drm/amd/display/dc/dcn21/dcn21_resource.c index 88d41a385add8..a4f37d83d5cc9 100644 --- a/drivers/gpu/drm/amd/display/dc/dcn21/dcn21_resource.c +++ b/drivers/gpu/drm/amd/display/dc/dcn21/dcn21_resource.c @@ -1184,6 +1184,9 @@ bool dcn21_validate_bandwidth(struct dc *dc, struct dc_state *context, BW_VAL_TRACE_COUNT(); + /*Unsafe due to current pipe merge and split logic*/ + ASSERT(context != dc->current_state); + out = dcn20_fast_validate_bw(dc, context, pipes, &pipe_cnt, pipe_split_from, &vlevel); if (pipe_cnt == 0)