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authorFigo.zhang <figo1802@gmail.com>2009-06-16 13:31:29 -0300
committerMauro Carvalho Chehab <mchehab@redhat.com>2009-06-16 19:14:44 -0300
commit9fd6418a6a7655b69cfa0ae27a3639a6d0b2924f (patch)
tree3b3754a6518f7cefb130b314199733daaf831d2b /drivers/media/video/cx88/cx88-video.c
parent1c905a4522a3913cf321365c5bb62eb2f70d55d9 (diff)
V4L/DVB (12004): poll method lose race condition
bttv-driver.c,cx23885-video.c,cx88-video.c: poll method lose race condition for capture video. Signed-off-by: Figo.zhang <figo1802@gmail.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Diffstat (limited to 'drivers/media/video/cx88/cx88-video.c')
-rw-r--r--drivers/media/video/cx88/cx88-video.c14
1 files changed, 10 insertions, 4 deletions
diff --git a/drivers/media/video/cx88/cx88-video.c b/drivers/media/video/cx88/cx88-video.c
index d6d6d13a6a6..0ccac702bea 100644
--- a/drivers/media/video/cx88/cx88-video.c
+++ b/drivers/media/video/cx88/cx88-video.c
@@ -869,6 +869,7 @@ video_poll(struct file *file, struct poll_table_struct *wait)
{
struct cx8800_fh *fh = file->private_data;
struct cx88_buffer *buf;
+ unsigned int rc = POLLERR;
if (V4L2_BUF_TYPE_VBI_CAPTURE == fh->type) {
if (!res_get(fh->dev,fh,RESOURCE_VBI))
@@ -876,22 +877,27 @@ video_poll(struct file *file, struct poll_table_struct *wait)
return videobuf_poll_stream(file, &fh->vbiq, wait);
}
+ mutex_lock(&fh->vidq.vb_lock);
if (res_check(fh,RESOURCE_VIDEO)) {
/* streaming capture */
if (list_empty(&fh->vidq.stream))
- return POLLERR;
+ goto done;
buf = list_entry(fh->vidq.stream.next,struct cx88_buffer,vb.stream);
} else {
/* read() capture */
buf = (struct cx88_buffer*)fh->vidq.read_buf;
if (NULL == buf)
- return POLLERR;
+ goto done;
}
poll_wait(file, &buf->vb.done, wait);
if (buf->vb.state == VIDEOBUF_DONE ||
buf->vb.state == VIDEOBUF_ERROR)
- return POLLIN|POLLRDNORM;
- return 0;
+ rc = POLLIN|POLLRDNORM;
+ else
+ rc = 0;
+done:
+ mutex_unlock(&fh->vidq.vb_lock);
+ return rc;
}
static int video_release(struct file *file)