drm/amd/display: Add NULL checks for vblank workqueue
[Why]
If we're running a headless config with 0 links then the vblank
workqueue will be NULL - causing a NULL pointer exception during
any commit.
[How]
Guard access to the workqueue if it's NULL and don't queue or flush
work if it is.
Reported-by: Mike Lothian <mike@fireburn.co.uk>
BugLink: https://gitlab.freedesktop.org/drm/amd/-/issues/1700
Fixes: 58aa1c50e5a231 ("drm/amd/display: Use vblank control events for PSR enable/disable")
Signed-off-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Reviewed-by: Harry Wentland <Harry.Wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
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 5336372..24002a9 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -6185,21 +6185,23 @@ static inline int dm_set_vblank(struct drm_crtc *crtc, bool enable)
return 0;
#if defined(CONFIG_DRM_AMD_DC_DCN)
- work = kzalloc(sizeof(*work), GFP_ATOMIC);
- if (!work)
- return -ENOMEM;
+ if (dm->vblank_control_workqueue) {
+ work = kzalloc(sizeof(*work), GFP_ATOMIC);
+ if (!work)
+ return -ENOMEM;
- INIT_WORK(&work->work, vblank_control_worker);
- work->dm = dm;
- work->acrtc = acrtc;
- work->enable = enable;
+ INIT_WORK(&work->work, vblank_control_worker);
+ work->dm = dm;
+ work->acrtc = acrtc;
+ work->enable = enable;
- if (acrtc_state->stream) {
- dc_stream_retain(acrtc_state->stream);
- work->stream = acrtc_state->stream;
+ if (acrtc_state->stream) {
+ dc_stream_retain(acrtc_state->stream);
+ work->stream = acrtc_state->stream;
+ }
+
+ queue_work(dm->vblank_control_workqueue, &work->work);
}
-
- queue_work(dm->vblank_control_workqueue, &work->work);
#endif
return 0;
@@ -8809,7 +8811,8 @@ static void amdgpu_dm_commit_planes(struct drm_atomic_state *state,
* If PSR or idle optimizations are enabled then flush out
* any pending work before hardware programming.
*/
- flush_workqueue(dm->vblank_control_workqueue);
+ if (dm->vblank_control_workqueue)
+ flush_workqueue(dm->vblank_control_workqueue);
#endif
bundle->stream_update.stream = acrtc_state->stream;
@@ -9144,7 +9147,8 @@ static void amdgpu_dm_atomic_commit_tail(struct drm_atomic_state *state)
/* if there mode set or reset, disable eDP PSR */
if (mode_set_reset_required) {
#if defined(CONFIG_DRM_AMD_DC_DCN)
- flush_workqueue(dm->vblank_control_workqueue);
+ if (dm->vblank_control_workqueue)
+ flush_workqueue(dm->vblank_control_workqueue);
#endif
amdgpu_dm_psr_disable_all(dm);
}
