V4L/DVB (11852): saa7134-video.c: poll method lose race condition
saa7134-video.c: poll method lose race condition
Signed-off-by: Figo Zhang <figo.zhang@kolorific.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/media/video/saa7134/saa7134-video.c b/drivers/media/video/saa7134/saa7134-video.c
index 493cad9..ceae3c8 100644
--- a/drivers/media/video/saa7134/saa7134-video.c
+++ b/drivers/media/video/saa7134/saa7134-video.c
@@ -1423,11 +1423,13 @@
{
struct saa7134_fh *fh = file->private_data;
struct videobuf_buffer *buf = NULL;
+ unsigned int rc = 0;
if (V4L2_BUF_TYPE_VBI_CAPTURE == fh->type)
return videobuf_poll_stream(file, &fh->vbi, wait);
if (res_check(fh,RESOURCE_VIDEO)) {
+ mutex_lock(&fh->cap.vb_lock);
if (!list_empty(&fh->cap.stream))
buf = list_entry(fh->cap.stream.next, struct videobuf_buffer, stream);
} else {
@@ -1446,13 +1448,14 @@
}
if (!buf)
- return POLLERR;
+ goto err;
poll_wait(file, &buf->done, wait);
if (buf->state == VIDEOBUF_DONE ||
buf->state == VIDEOBUF_ERROR)
- return POLLIN|POLLRDNORM;
- return 0;
+ rc = POLLIN|POLLRDNORM;
+ mutex_unlock(&fh->cap.vb_lock);
+ return rc;
err:
mutex_unlock(&fh->cap.vb_lock);