drm/nouveau: complain loudly if buffer is pinned during destruction

Shouldn't happen, and we invert the struct_mutex with reservation here,
potentially leading to deadlocks. Once reservations become lockdep annotated,
lockdep will go splat on this.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@canonical.com>
Acked-by: Ben Skeggs <bskeggs@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 2 insertions, 1 deletions

diff --git a/drivers/gpu/drm/nouveau/nouveau_gem.c b/drivers/gpu/drm/nouveau/nouveau_gem.c
index b4b4d0c1f4af..705470600e48 100644
--- a/drivers/gpu/drm/nouveau/nouveau_gem.c
+++ b/drivers/gpu/drm/nouveau/nouveau_gem.c
@@ -50,7 +50,8 @@ nouveau_gem_object_del(struct drm_gem_object *gem)
                 return;
         nvbo->gem = NULL;
 
-        if (unlikely(nvbo->pin_refcnt)) {
+        /* Lockdep hates you for doing reserve with gem object lock held */
+        if (WARN_ON_ONCE(nvbo->pin_refcnt)) {
                 nvbo->pin_refcnt = 1;
                 nouveau_bo_unpin(nvbo);
         }