V4L/DVB: uvcvideo: Use POLLOUT and POLLWRNORM for output devices

The V4L2 specification requires drivers to use the write events in the
file operations poll handler for output devices. The uvcvideo driver
erroneously used read events for all devices. Fix this.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

diff --git a/drivers/media/video/uvc/uvc_queue.c b/drivers/media/video/uvc/uvc_queue.c
index 4a925a3..133c78d 100644 (file)
--- a/drivers/media/video/uvc/uvc_queue.c
+++ b/drivers/media/video/uvc/uvc_queue.c
@@ -388,8 +388,12 @@ unsigned int uvc_queue_poll(struct uvc_video_queue *queue, struct file *file,
 
        poll_wait(file, &buf->wait, wait);
        if (buf->state == UVC_BUF_STATE_DONE ||
-           buf->state == UVC_BUF_STATE_ERROR)
-               mask |= POLLIN | POLLRDNORM;
+           buf->state == UVC_BUF_STATE_ERROR) {
+               if (queue->type == V4L2_BUF_TYPE_VIDEO_CAPTURE)
+                       mask |= POLLIN | POLLRDNORM;
+               else
+                       mask |= POLLOUT | POLLWRNORM;
+       }
 
 done:
        mutex_unlock(&queue->mutex);