Hi Hans, I just fixed a crash in the out of tree driver which is caused by: a10b21532574 ("media: vb2: add (un)prepare_streaming queue ops") I know that breaking out of tree code is fine / not our problem, but I wonder if this maybe affects some in tree code too ? The problem with the out of tree driver is that it used vb2_queue->streaming inside the buf_queue() callback to determine if the buffer was being pre-queued (from vb2_start_streaming() calling __enqueue_in_driver()) before the start_streaming queue-op is called. Or if it was being queued after the start_streaming queue-op has been called. With vb2_queue->streaming now being set before the __enqueue_in_driver() calls in vb2_start_streaming() this broke and it went down the route to see if there was space available in the hw-queue which NULL pointer deref-ed because the hw-queue had not been setup yet (more or less). This is fixed now as far as the ipu6 driver is concerned, but I wonder if we may not have in tree drivers making similar assumptions about vb2_queue->streaming in their buf_queue() callbacks ? Regards, Hans