Patch "drm/amd/display: Skip on writeback when it's not applicable" has been added to the 6.6-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    drm/amd/display: Skip on writeback when it's not applicable

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-skip-on-writeback-when-it-s-not-appl.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 963007fcbd7890834c9672061c36f423647542fb
Author: Alex Hung <alex.hung@xxxxxxx>
Date:   Fri Mar 15 21:25:25 2024 -0600

    drm/amd/display: Skip on writeback when it's not applicable
    
    [ Upstream commit ecedd99a9369fb5cde601ae9abd58bca2739f1ae ]
    
    [WHY]
    dynamic memory safety error detector (KASAN) catches and generates error
    messages "BUG: KASAN: slab-out-of-bounds" as writeback connector does not
    support certain features which are not initialized.
    
    [HOW]
    Skip them when connector type is DRM_MODE_CONNECTOR_WRITEBACK.
    
    Link: https://gitlab.freedesktop.org/drm/amd/-/issues/3199
    Reviewed-by: Harry Wentland <harry.wentland@xxxxxxx>
    Reviewed-by: Rodrigo Siqueira <rodrigo.siqueira@xxxxxxx>
    Acked-by: Roman Li <roman.li@xxxxxxx>
    Signed-off-by: Alex Hung <alex.hung@xxxxxxx>
    Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
index 3442e08f47876..98dd07e3726af 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -2974,6 +2974,10 @@ static int dm_resume(void *handle)
 	/* Do mst topology probing after resuming cached state*/
 	drm_connector_list_iter_begin(ddev, &iter);
 	drm_for_each_connector_iter(connector, &iter) {
+
+		if (connector->connector_type == DRM_MODE_CONNECTOR_WRITEBACK)
+			continue;
+
 		aconnector = to_amdgpu_dm_connector(connector);
 		if (aconnector->dc_link->type != dc_connection_mst_branch ||
 		    aconnector->mst_root)
@@ -5756,6 +5760,9 @@ get_highest_refresh_rate_mode(struct amdgpu_dm_connector *aconnector,
 		&aconnector->base.probed_modes :
 		&aconnector->base.modes;
 
+	if (aconnector->base.connector_type == DRM_MODE_CONNECTOR_WRITEBACK)
+		return NULL;
+
 	if (aconnector->freesync_vid_base.clock != 0)
 		return &aconnector->freesync_vid_base;
 
@@ -8445,6 +8452,9 @@ static void amdgpu_dm_commit_audio(struct drm_device *dev,
 			continue;
 
 notify:
+		if (connector->connector_type == DRM_MODE_CONNECTOR_WRITEBACK)
+			continue;
+
 		aconnector = to_amdgpu_dm_connector(connector);
 
 		mutex_lock(&adev->dm.audio_lock);