diff options
| author | Mauro Carvalho Chehab <mchehab@redhat.com> | 2009-06-16 16:31:29 +0000 |
|---|---|---|
| committer | Mauro Carvalho Chehab <mchehab@redhat.com> | 2009-06-16 16:31:29 +0000 |
| commit | 944b8fa4c78bec5e481f59eaa0c02d2928be6309 (patch) | |
| tree | dbf8df070217d6b21b5ed36ab99391e6ea3e64dc /linux/drivers/media/video/cx88 | |
| parent | 505dee96b5f86facce4200d260ffec2fb5a737b8 (diff) | |
| download | mediapointer-dvb-s2-944b8fa4c78bec5e481f59eaa0c02d2928be6309.tar.gz mediapointer-dvb-s2-944b8fa4c78bec5e481f59eaa0c02d2928be6309.tar.bz2 | |
poll method lose race condition
From: Figo.zhang <figo1802@gmail.com>
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 'linux/drivers/media/video/cx88')
| -rw-r--r-- | linux/drivers/media/video/cx88/cx88-video.c | 14 |
1 files changed, 10 insertions, 4 deletions
diff --git a/linux/drivers/media/video/cx88/cx88-video.c b/linux/drivers/media/video/cx88/cx88-video.c index 70b086fb7..a55053767 100644 --- a/linux/drivers/media/video/cx88/cx88-video.c +++ b/linux/drivers/media/video/cx88/cx88-video.c @@ -1095,6 +1095,7 @@ 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)) @@ -1102,22 +1103,27 @@ 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) |