drm/nouveau/disp: fix oops in destructor with headless cards

If init doesn't run then disp->outp might not be initialized, resulting
in an oops.

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

1 files changed, 4 insertions, 2 deletions

diff --git a/drivers/gpu/drm/nouveau/core/engine/disp/base.c b/drivers/gpu/drm/nouveau/core/engine/disp/base.c
index c41f656abe64..9c38c5e40500 100644
--- a/drivers/gpu/drm/nouveau/core/engine/disp/base.c
+++ b/drivers/gpu/drm/nouveau/core/engine/disp/base.c
@@ -99,8 +99,10 @@ _nouveau_disp_dtor(struct nouveau_object *object)
 
         nouveau_event_destroy(&disp->vblank);
 
-        list_for_each_entry_safe(outp, outt, &disp->outp, head) {
-                nouveau_object_ref(NULL, (struct nouveau_object **)&outp);
+        if (disp->outp.next) {
+                list_for_each_entry_safe(outp, outt, &disp->outp, head) {
+                        nouveau_object_ref(NULL, (struct nouveau_object **)&outp);
+                }
         }
 
         nouveau_engine_destroy(&disp->base);