Patch "drm/amd/display: Skip on writeback when it's not applicable" has been added to the 6.8-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 6.8-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-6.8 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 3230d3354c67860803e2eff7c500df804f84b763
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 0d3e553647993..9044214dfdbdf 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -3028,6 +3028,10 @@ 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)
@@ -5879,6 +5883,9 @@ 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;
 
@@ -8633,10 +8640,10 @@ static void amdgpu_dm_commit_audio(struct drm_device *dev,
 		if (!drm_atomic_crtc_needs_modeset(new_crtc_state))
 			continue;
 
+notify:
 		if (connector->connector_type == DRM_MODE_CONNECTOR_WRITEBACK)
 			continue;
 
-notify:
 		aconnector = to_amdgpu_dm_connector(connector);
 
 		mutex_lock(&adev->dm.audio_lock);