This is a note to let you know that I've just added the patch titled drm/amd/display: Fix stream->link_enc unassigned during stream removal to the 5.15-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-fix-stream-link_enc-unassigned-durin.patch and it can be found in the queue-5.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 6a6f972d42808d8883ea363e57aa4fd60bbd92a7 Author: Nicholas Kazlauskas <nicholas.kazlauskas@xxxxxxx> Date: Tue Jan 25 12:04:34 2022 -0500 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@xxxxxxx> Acked-by: Jasdeep Dhillon <jdhillon@xxxxxxx> Signed-off-by: Nicholas Kazlauskas <nicholas.kazlauskas@xxxxxxx> Tested-by: Daniel Wheeler <daniel.wheeler@xxxxxxx> Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx> Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> 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 e94546187cf15..7ae409f7dcf8d 100644 --- 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(