[PATCH 06/14] drm/amd/display: Force disable planes on any pipe split change

[Aurabindo Pillai]

From: Roman Li <Roman.Li at amd.com>

[Why]
In scenario when 1 display connected with pipe split (2 pipes in use)
and 3 new displays simultaneously hotplugged via MST hub (4 pipes in use),
mpcc may get reprogram to other vtg, remaining busy.
In this case waiting for mpcc idle timeouts with error like this:
[drm] REG_WAIT timeout 1us * 100000 tries - mpc2_assert_idle_mpcc
RIP: 0010:mpc2_assert_mpcc_idle_before_connect
Call Trace:
dcn20_update_mpcc
dcn20_program_front_end_for_ctx
dc_commit_state
amdgpu_dm_atomic_commit_tail
...

[How]
Add pipe split change condition to disable dangling plane.

Acked-by: Aurabindo Pillai <aurabindo.pillai at amd.com>
Signed-off-by: Roman Li <Roman.Li at amd.com>
Reviewed-by: Nicholas Kazlauskas <Nicholas.Kazlauskas at amd.com>
Reviewed-by: Dmytro Laktyushkin <Dmytro.Laktyushkin at amd.com>
---
 drivers/gpu/drm/amd/display/dc/core/dc.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/gpu/drm/amd/display/dc/core/dc.c b/drivers/gpu/drm/amd/display/dc/core/dc.c
index 12e5470fa567..11a00e4d9e81 100644
--- a/drivers/gpu/drm/amd/display/dc/core/dc.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc.c
@@ -1085,6 +1085,8 @@ static void disable_dangling_plane(struct dc *dc, struct dc_state *context)
 		struct dc_stream_state *old_stream =
 				dc->current_state->res_ctx.pipe_ctx[i].stream;
 		bool should_disable = true;
+		bool pipe_split_change =
+			context->res_ctx.pipe_ctx[i].top_pipe != dc->current_state->res_ctx.pipe_ctx[i].top_pipe;
 
 		for (j = 0; j < context->stream_count; j++) {
 			if (old_stream == context->streams[j]) {
@@ -1092,6 +1094,9 @@ static void disable_dangling_plane(struct dc *dc, struct dc_state *context)
 				break;
 			}
 		}
+		if (!should_disable && pipe_split_change)
+			should_disable = true;
+
 		if (should_disable && old_stream) {
 			dc_rem_all_planes_for_stream(dc, old_stream, dangling_context);
 			disable_all_writeback_pipes_for_stream(dc, old_stream, dangling_context);
-- 
2.30.2