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>
diff --git a/drivers/media/video/bt8xx/bttv-driver.c b/drivers/media/video/bt8xx/bttv-driver.c
index 7c1f826..5eb1464 100644
--- a/drivers/media/video/bt8xx/bttv-driver.c
+++ b/drivers/media/video/bt8xx/bttv-driver.c
@@ -3152,6 +3152,7 @@
struct bttv_fh *fh = file->private_data;
struct bttv_buffer *buf;
enum v4l2_field field;
+ unsigned int rc = POLLERR;
if (V4L2_BUF_TYPE_VBI_CAPTURE == fh->type) {
if (!check_alloc_btres(fh->btv,fh,RESOURCE_VBI))
@@ -3160,9 +3161,10 @@
}
if (check_btres(fh,RESOURCE_VIDEO_STREAM)) {
+ mutex_lock(&fh->cap.vb_lock);
/* streaming capture */
if (list_empty(&fh->cap.stream))
- return POLLERR;
+ goto err;
buf = list_entry(fh->cap.stream.next,struct bttv_buffer,vb.stream);
} else {
/* read() capture */
@@ -3191,11 +3193,12 @@
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;
err:
mutex_unlock(&fh->cap.vb_lock);
- return POLLERR;
+ return rc;
}
static int bttv_open(struct file *file)
diff --git a/drivers/media/video/cx23885/cx23885-video.c b/drivers/media/video/cx23885/cx23885-video.c
index 68068c6..66bbd2e 100644
--- a/drivers/media/video/cx23885/cx23885-video.c
+++ b/drivers/media/video/cx23885/cx23885-video.c
@@ -796,6 +796,7 @@
{
struct cx23885_fh *fh = file->private_data;
struct cx23885_buffer *buf;
+ unsigned int rc = POLLERR;
if (V4L2_BUF_TYPE_VBI_CAPTURE == fh->type) {
if (!res_get(fh->dev, fh, RESOURCE_VBI))
@@ -803,23 +804,28 @@
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 cx23885_buffer, vb.stream);
} else {
/* read() capture */
buf = (struct cx23885_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)
diff --git a/drivers/media/video/cx88/cx88-video.c b/drivers/media/video/cx88/cx88-video.c
index d6d6d13..0ccac70 100644
--- a/drivers/media/video/cx88/cx88-video.c
+++ b/drivers/media/video/cx88/cx88-video.c
@@ -869,6 +869,7 @@
{
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 @@
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)