drm/ttm: Make sure a sync object doesn't disappear while we use it
The sync object may disappear as soon as we release the bo::lock, so
take a reference on it while we use it.
One option would be to call sync_object_flush() before releasing the bo::lock,
but that would put an atomic requirement on that function.
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c
index a32fe41..340dfb1 100644
--- a/drivers/gpu/drm/ttm/ttm_bo.c
+++ b/drivers/gpu/drm/ttm/ttm_bo.c
@@ -458,7 +458,7 @@
struct ttm_bo_device *bdev = bo->bdev;
struct ttm_bo_global *glob = bo->glob;
struct ttm_bo_driver *driver;
- void *sync_obj;
+ void *sync_obj = NULL;
void *sync_obj_arg;
int put_count;
int ret;
@@ -493,17 +493,20 @@
spin_lock(&glob->lru_lock);
}
queue:
- sync_obj = bo->sync_obj;
- sync_obj_arg = bo->sync_obj_arg;
driver = bdev->driver;
+ if (bo->sync_obj)
+ sync_obj = driver->sync_obj_ref(bo->sync_obj);
+ sync_obj_arg = bo->sync_obj_arg;
kref_get(&bo->list_kref);
list_add_tail(&bo->ddestroy, &bdev->ddestroy);
spin_unlock(&glob->lru_lock);
spin_unlock(&bo->lock);
- if (sync_obj)
+ if (sync_obj) {
driver->sync_obj_flush(sync_obj, sync_obj_arg);
+ driver->sync_obj_unref(&sync_obj);
+ }
schedule_delayed_work(&bdev->wq,
((HZ / 100) < 1) ? 1 : HZ / 100);
}