diff options
Diffstat (limited to 'drivers/media/v4l2-core/v4l2-mem2mem.c')
| -rw-r--r-- | drivers/media/v4l2-core/v4l2-mem2mem.c | 15 |
1 files changed, 12 insertions, 3 deletions
diff --git a/drivers/media/v4l2-core/v4l2-mem2mem.c b/drivers/media/v4l2-core/v4l2-mem2mem.c index b221b4e438a1..e7f4bf5bc8dd 100644 --- a/drivers/media/v4l2-core/v4l2-mem2mem.c +++ b/drivers/media/v4l2-core/v4l2-mem2mem.c @@ -887,9 +887,6 @@ static __poll_t v4l2_m2m_poll_for_data(struct file *file, src_q = v4l2_m2m_get_src_vq(m2m_ctx); dst_q = v4l2_m2m_get_dst_vq(m2m_ctx); - poll_wait(file, &src_q->done_wq, wait); - poll_wait(file, &dst_q->done_wq, wait); - /* * There has to be at least one buffer queued on each queued_list, which * means either in driver already or waiting for driver to claim it @@ -922,9 +919,21 @@ __poll_t v4l2_m2m_poll(struct file *file, struct v4l2_m2m_ctx *m2m_ctx, struct poll_table_struct *wait) { struct video_device *vfd = video_devdata(file); + struct vb2_queue *src_q = v4l2_m2m_get_src_vq(m2m_ctx); + struct vb2_queue *dst_q = v4l2_m2m_get_dst_vq(m2m_ctx); __poll_t req_events = poll_requested_events(wait); __poll_t rc = 0; + /* + * poll_wait() MUST be called on the first invocation on all the + * potential queues of interest, even if we are not interested in their + * events during this first call. Failure to do so will result in + * queue's events to be ignored because the poll_table won't be capable + * of adding new wait queues thereafter. + */ + poll_wait(file, &src_q->done_wq, wait); + poll_wait(file, &dst_q->done_wq, wait); + if (req_events & (EPOLLOUT | EPOLLWRNORM | EPOLLIN | EPOLLRDNORM)) rc = v4l2_m2m_poll_for_data(file, m2m_ctx, wait); |