[media] vb2: call buf_finish from __queue_cancel

If a queue was canceled, then the buf_finish op was never called for the
pending buffers. So add this call to queue_cancel. Before calling buf_finish
set the buffer state to PREPARED, which is the correct state. That way the
states DONE and ERROR will only be seen in buf_finish if streaming is in
progress.

Since buf_finish can now be called from non-streaming state we need to
adapt the handful of drivers that actually need to know this.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>

drivers/media/parport/bw-qcam.c

@@ -674,6 +674,9 @@ static void buffer_finish(struct vb2_buffer *vb)
 	int size = vb->vb2_queue->plane_sizes[0];
 	int len;
 
+	if (!vb2_is_streaming(vb->vb2_queue))
+		return;
+
 	mutex_lock(&qcam->lock);
 	parport_claim_or_block(qcam->pdev);
 

drivers/media/pci/sta2x11/sta2x11_vip.c

@@ -337,7 +337,8 @@ static void buffer_finish(struct vb2_buffer *vb)
 	list_del_init(&vip_buf->list);
 	spin_unlock(&vip->lock);
 
-	vip_active_buf_next(vip);
+	if (vb2_is_streaming(vb->vb2_queue))
+		vip_active_buf_next(vip);
 }
 
 static int start_streaming(struct vb2_queue *vq, unsigned int count)

drivers/media/usb/uvc/uvc_queue.c

@@ -113,7 +113,8 @@ static void uvc_buffer_finish(struct vb2_buffer *vb)
 			container_of(queue, struct uvc_streaming, queue);
 	struct uvc_buffer *buf = container_of(vb, struct uvc_buffer, buf);
 
-	uvc_video_clock_update(stream, &vb->v4l2_buf, buf);
+	if (vb->state == VB2_BUF_STATE_DONE)
+		uvc_video_clock_update(stream, &vb->v4l2_buf, buf);
 }
 
 static void uvc_wait_prepare(struct vb2_queue *vq)

drivers/media/v4l2-core/videobuf2-core.c

@@ -1929,9 +1929,22 @@ static void __vb2_queue_cancel(struct vb2_queue *q)
 
 	/*
 	 * Reinitialize all buffers for next use.
+	 * Make sure to call buf_finish for any queued buffers. Normally
+	 * that's done in dqbuf, but that's not going to happen when we
+	 * cancel the whole queue. Note: this code belongs here, not in
+	 * __vb2_dqbuf() since in vb2_internal_dqbuf() there is a critical
+	 * call to __fill_v4l2_buffer() after buf_finish(). That order can't
+	 * be changed, so we can't move the buf_finish() to __vb2_dqbuf().
 	 */
-	for (i = 0; i < q->num_buffers; ++i)
-		__vb2_dqbuf(q->bufs[i]);
+	for (i = 0; i < q->num_buffers; ++i) {
+		struct vb2_buffer *vb = q->bufs[i];
+
+		if (vb->state != VB2_BUF_STATE_DEQUEUED) {
+			vb->state = VB2_BUF_STATE_PREPARED;
+			call_vb_qop(vb, buf_finish, vb);
+		}
+		__vb2_dqbuf(vb);
+	}
 }
 
 static int vb2_internal_streamon(struct vb2_queue *q, enum v4l2_buf_type type)

include/media/videobuf2-core.h

@@ -276,7 +276,15 @@ struct vb2_buffer {
  *			in driver; optional
  * @buf_finish:		called before every dequeue of the buffer back to
  *			userspace; drivers may perform any operations required
- *			before userspace accesses the buffer; optional
+ *			before userspace accesses the buffer; optional. The
+ *			buffer state can be one of the following: DONE and
+ *			ERROR occur while streaming is in progress, and the
+ *			PREPARED state occurs when the queue has been canceled
+ *			and all pending buffers are being returned to their
+ *			default DEQUEUED state. Typically you only have to do
+ *			something if the state is VB2_BUF_STATE_DONE, since in
+ *			all other cases the buffer contents will be ignored
+ *			anyway.
  * @buf_cleanup:	called once before the buffer is freed; drivers may
  *			perform any additional cleanup; optional
  * @start_streaming:	called once to enter 'streaming' state; the driver may