drm/amd/display: Fix stream->link_enc unassigned during stream removal

[ Upstream commit 3743e7f6fcb938b7d8b7967e6a9442805e269b3d ]

[Why]
Found when running igt@kms_atomic.

Userspace attempts to do a TEST_COMMIT when 0 streams which calls
dc_remove_stream_from_ctx. This in turn calls link_enc_unassign
which ends up modifying stream->link = NULL directly, causing the
global link_enc to be removed preventing further link activity
and future link validation from passing.

[How]
We take care of link_enc unassignment at the start of
link_enc_cfg_link_encs_assign so this call is no longer necessary.

Fixes global state from being modified while unlocked.

Reviewed-by: Jimmy Kizito <Jimmy.Kizito@amd.com>
Acked-by: Jasdeep Dhillon <jdhillon@amd.com>
Signed-off-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_resource.c b/drivers/gpu/drm/amd/display/dc/core/dc_resource.c
index e945461..7ae409f 100644 (file)
--- a/drivers/gpu/drm/amd/display/dc/core/dc_resource.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc_resource.c
@@ -1799,9 +1799,6 @@ enum dc_status dc_remove_stream_from_ctx(
                                dc->res_pool,
                        del_pipe->stream_res.stream_enc,
                        false);
-       /* Release link encoder from stream in new dc_state. */
-       if (dc->res_pool->funcs->link_enc_unassign)
-               dc->res_pool->funcs->link_enc_unassign(new_ctx, del_pipe->stream);
 
        if (del_pipe->stream_res.audio)
                update_audio_usage(