From: George Shen george.shen@amd.com
[ Upstream commit 3c1a467372e0c356b1d3c59f6d199ed5a6612dd1 ]
[Why & How] When MST config is unplugged/replugged too quickly, it can potentially result in a scenario where previous DC state has not been reset before the HPD link detection sequence begins. In this case, driver will disable the streams/link prior to re-enabling the link for link training.
There is a bug in the current logic that does not account for the fact that current_state can be released and cleared prior to swapping to a new state (resulting in the pipe_ctx stream pointers to be cleared) in between disabling streams.
To resolve this, cache the original streams prior to committing any stream updates.
Reviewed-by: Wenjing Liu wenjing.liu@amd.com Signed-off-by: George Shen george.shen@amd.com Signed-off-by: Ray Wu ray.wu@amd.com Tested-by: Daniel Wheeler daniel.wheeler@amd.com Signed-off-by: Alex Deucher alexander.deucher@amd.com (cherry picked from commit 1561782686ccc36af844d55d31b44c938dd412dc) Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpu/drm/amd/display/dc/link/link_dpms.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/amd/display/dc/link/link_dpms.c b/drivers/gpu/drm/amd/display/dc/link/link_dpms.c index 4901e27f678bc..9b470812d96a5 100644 --- a/drivers/gpu/drm/amd/display/dc/link/link_dpms.c +++ b/drivers/gpu/drm/amd/display/dc/link/link_dpms.c @@ -145,6 +145,7 @@ void link_blank_dp_stream(struct dc_link *link, bool hw_init) void link_set_all_streams_dpms_off_for_link(struct dc_link *link) { struct pipe_ctx *pipes[MAX_PIPES]; + struct dc_stream_state *streams[MAX_PIPES]; struct dc_state *state = link->dc->current_state; uint8_t count; int i; @@ -157,10 +158,18 @@ void link_set_all_streams_dpms_off_for_link(struct dc_link *link)
link_get_master_pipes_with_dpms_on(link, state, &count, pipes);
+ /* The subsequent call to dc_commit_updates_for_stream for a full update + * will release the current state and swap to a new state. Releasing the + * current state results in the stream pointers in the pipe_ctx structs + * to be zero'd. Hence, cache all streams prior to dc_commit_updates_for_stream. + */ + for (i = 0; i < count; i++) + streams[i] = pipes[i]->stream; + for (i = 0; i < count; i++) { - stream_update.stream = pipes[i]->stream; + stream_update.stream = streams[i]; dc_commit_updates_for_stream(link->ctx->dc, NULL, 0, - pipes[i]->stream, &stream_update, + streams[i], &stream_update, state); }