5 files changed, 31 insertions, 5 deletions

diff --git a/drivers/media/parport/bw-qcam.c b/drivers/media/parport/bw-qcam.c
index cf2db63da3b1..8a0e84c7d495 100644
--- a/drivers/media/parport/bw-qcam.c
+++ b/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);
 
diff --git a/drivers/media/pci/sta2x11/sta2x11_vip.c b/drivers/media/pci/sta2x11/sta2x11_vip.c
index e66556cae7ea..bb11443ed63e 100644
--- a/drivers/media/pci/sta2x11/sta2x11_vip.c
+++ b/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)
diff --git a/drivers/media/usb/uvc/uvc_queue.c b/drivers/media/usb/uvc/uvc_queue.c
index 26172cbcf096..6e92d2080255 100644
--- a/drivers/media/usb/uvc/uvc_queue.c
+++ b/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)
diff --git a/drivers/media/v4l2-core/videobuf2-core.c b/drivers/media/v4l2-core/videobuf2-core.c
index 2be3cfec2ac8..16ae66f5584f 100644
--- a/drivers/media/v4l2-core/videobuf2-core.c
+++ b/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)
diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h
index 8d62a51cb7a0..2ffcb81aee9c 100644
--- a/include/media/videobuf2-core.h
+++ b/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