Commit ce271b40 authored Jul 30, 2020 by Qingqing Zhuo Committed by Alex Deucher Aug 17, 2020

drm/amd/display: Screen corruption on dual displays (DP+USB-C)



[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@amd.com>
Reviewed-by: Nicholas Kazlauskas <Nicholas.Kazlauskas@amd.com>
Acked-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

parent ccc87505

drivers/gpu/drm/amd/display/dc/core/dc.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -2636,7 +2636,7 @@ 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);

drivers/gpu/drm/amd/display/dc/dcn20/dcn20_resource.c

+3 −0

Original line number	Diff line number	Diff line
		@@ -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);
		}

drivers/gpu/drm/amd/display/dc/dcn21/dcn21_resource.c

+3 −0

Original line number	Diff line number	Diff line
		@@ -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)