Patch "drm/amd/display: fix access hdcp_workqueue assert" has been added to the 5.15-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: fix access hdcp_workqueue assert

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-access-hdcp_workqueue-assert.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 0418be890039a4e8a98a6e8fe276ffb553106be4
Author: Hersen Wu <hersenxs.wu@xxxxxxx>
Date:   Tue Mar 28 10:45:24 2023 -0400

    drm/amd/display: fix access hdcp_workqueue assert
    
    [ Upstream commit cdff36a0217aadf5cbc167893ad1c0da869619cb ]
    
    [Why] hdcp are enabled for asics from raven. for old asics
    which hdcp are not enabled, hdcp_workqueue are null. some
    access to hdcp work queue are not guarded with pointer check.
    
    [How] add hdcp_workqueue pointer check before access workqueue.
    
    Reviewed-by: Bhawanpreet Lakha <Bhawanpreet.Lakha@xxxxxxx>
    Acked-by: Qingqing Zhuo <qingqing.zhuo@xxxxxxx>
    Signed-off-by: Hersen Wu <hersenxs.wu@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/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
index 65f9e7012f6c4..4cf33abfb7cca 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -9634,6 +9634,9 @@ static void amdgpu_dm_atomic_commit_tail(struct drm_atomic_state *state)
 		struct amdgpu_crtc *acrtc = to_amdgpu_crtc(dm_new_con_state->base.crtc);
 		struct amdgpu_dm_connector *aconnector = to_amdgpu_dm_connector(connector);
 
+		if (!adev->dm.hdcp_workqueue)
+			continue;
+
 		pr_debug("[HDCP_DM] -------------- i : %x ----------\n", i);
 
 		if (!connector)
@@ -9682,6 +9685,9 @@ static void amdgpu_dm_atomic_commit_tail(struct drm_atomic_state *state)
 		struct amdgpu_crtc *acrtc = to_amdgpu_crtc(dm_new_con_state->base.crtc);
 		struct amdgpu_dm_connector *aconnector = to_amdgpu_dm_connector(connector);
 
+		if (!adev->dm.hdcp_workqueue)
+			continue;
+
 		new_crtc_state = NULL;
 		old_crtc_state = NULL;
 
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c
index e1e0be6dd22ca..0b58a93864490 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c
@@ -331,13 +331,17 @@ static int dm_dp_mst_get_modes(struct drm_connector *connector)
 		if (aconnector->dc_sink && connector->state) {
 			struct drm_device *dev = connector->dev;
 			struct amdgpu_device *adev = drm_to_adev(dev);
-			struct hdcp_workqueue *hdcp_work = adev->dm.hdcp_workqueue;
-			struct hdcp_workqueue *hdcp_w = &hdcp_work[aconnector->dc_link->link_index];
 
-			connector->state->hdcp_content_type =
-			hdcp_w->hdcp_content_type[connector->index];
-			connector->state->content_protection =
-			hdcp_w->content_protection[connector->index];
+			if (adev->dm.hdcp_workqueue) {
+				struct hdcp_workqueue *hdcp_work = adev->dm.hdcp_workqueue;
+				struct hdcp_workqueue *hdcp_w =
+					&hdcp_work[aconnector->dc_link->link_index];
+
+				connector->state->hdcp_content_type =
+				hdcp_w->hdcp_content_type[connector->index];
+				connector->state->content_protection =
+				hdcp_w->content_protection[connector->index];
+			}
 		}
 #endif