drm/radeon/kms: take vram mutex pointer before derefing object.

since derefing the object might free it.

Signed-off-by: Dave Airlie <airlied@redhat.com>

diff --git a/drivers/gpu/drm/radeon/radeon_object.c b/drivers/gpu/drm/radeon/radeon_object.c
index 06def70..a8d18bc 100644 (file)
--- a/drivers/gpu/drm/radeon/radeon_object.c
+++ b/drivers/gpu/drm/radeon/radeon_object.c
@@ -168,13 +168,15 @@ void radeon_bo_kunmap(struct radeon_bo *bo)
 void radeon_bo_unref(struct radeon_bo **bo)
 {
        struct ttm_buffer_object *tbo;
+       struct radeon_device *rdev;
 
        if ((*bo) == NULL)
                return;
+       rdev = (*bo)->rdev;
        tbo = &((*bo)->tbo);
-       mutex_lock(&(*bo)->rdev->vram_mutex);
+       mutex_lock(&rdev->vram_mutex);
        ttm_bo_unref(&tbo);
-       mutex_unlock(&(*bo)->rdev->vram_mutex);
+       mutex_unlock(&rdev->vram_mutex);
        if (tbo == NULL)
                *bo = NULL;
 }