This is a note to let you know that I've just added the patch titled
drm/amd/display: use preferred link settings for dp signal only
to the 6.6-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-use-preferred-link-settings-for-dp-s.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 44d0e072a035ed61dabef9dda72c9f3fec69a9cc
Author: Wenjing Liu <wenjing.liu@xxxxxxx>
Date: Wed May 29 12:20:41 2024 -0400
drm/amd/display: use preferred link settings for dp signal only
[ Upstream commit abf34ca465f5cd182b07701d3f3d369c0fc04723 ]
[why]
We set preferred link settings for virtual signal. However we don't support
virtual signal for UHBR link rate. If preferred is set to UHBR link rate, we
will allow virtual signal with UHBR link rate which causes system crashes.
Reviewed-by: Dillon Varone <dillon.varone@xxxxxxx>
Acked-by: Zaeem Mohamed <zaeem.mohamed@xxxxxxx>
Signed-off-by: Wenjing Liu <wenjing.liu@xxxxxxx>
Tested-by: Daniel Wheeler <daniel.wheeler@xxxxxxx>
Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_capability.c b/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_capability.c
index 16f4865e4246..3d589072fe30 100644
--- a/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_capability.c
+++ b/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_capability.c
@@ -908,21 +908,17 @@ bool link_decide_link_settings(struct dc_stream_state *stream,
memset(link_setting, 0, sizeof(*link_setting));
- /* if preferred is specified through AMDDP, use it, if it's enough
- * to drive the mode
- */
- if (link->preferred_link_setting.lane_count !=
- LANE_COUNT_UNKNOWN &&
- link->preferred_link_setting.link_rate !=
- LINK_RATE_UNKNOWN) {
+ if (dc_is_dp_signal(stream->signal) &&
+ link->preferred_link_setting.lane_count != LANE_COUNT_UNKNOWN &&
+ link->preferred_link_setting.link_rate != LINK_RATE_UNKNOWN) {
+ /* if preferred is specified through AMDDP, use it, if it's enough
+ * to drive the mode
+ */
*link_setting = link->preferred_link_setting;
- return true;
- }
-
- /* MST doesn't perform link training for now
- * TODO: add MST specific link training routine
- */
- if (stream->signal == SIGNAL_TYPE_DISPLAY_PORT_MST) {
+ } else if (stream->signal == SIGNAL_TYPE_DISPLAY_PORT_MST) {
+ /* MST doesn't perform link training for now
+ * TODO: add MST specific link training routine
+ */
decide_mst_link_settings(link, link_setting);
} else if (link->connector_signal == SIGNAL_TYPE_EDP) {
/* enable edp link optimization for DSC eDP case */
