drm/xe/ufence: Warn if mmget_not_zero() fails

This shouldn't happen but seen this while debugging ufence timeout
issue time to time so log it to isolate this particular case.

v2: s/XE_WARN_ON/drm_dbg(Maarten)

Link: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/1630
Cc: Francois Dugast <francois.dugast@intel.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Francois Dugast <francois.dugast@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20241016082304.66009-3-nirmoy.das@intel.com
Signed-off-by: Nirmoy Das <nirmoy.das@intel.com>

diff --git a/drivers/gpu/drm/xe/xe_sync.c b/drivers/gpu/drm/xe/xe_sync.c
index 2e72c06fd40d07c63ba5876f1663acefb97dea5c..a90480c6aecf563a2eab9007b6af9a5a04f2c123 100644 (file)
--- a/drivers/gpu/drm/xe/xe_sync.c
+++ b/drivers/gpu/drm/xe/xe_sync.c
@@ -83,6 +83,8 @@ static void user_fence_worker(struct work_struct *w)
                        XE_WARN_ON("Copy to user failed");
                kthread_unuse_mm(ufence->mm);
                mmput(ufence->mm);
+       } else {
+               drm_dbg(&ufence->xe->drm, "mmget_not_zero() failed, ufence wasn't signaled\n");
        }
 
        wake_up_all(&ufence->xe->ufence_wq);