V4L/DVB (6275): V4L: vivi.c remove the "resource" locking
The "resource" locking in vivi isn't needed since
streamon/streamoff/read_stream do mutual exclusion using
q->reading/q->streaming.
Plus it is sort of broken:
a) res_locked() use in vivi_read() is racey.
b) res_free() calls mutex_lock twice causing streamoff to break
Signed-off-by: Brandon Philips <bphilips@suse.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
diff --git a/drivers/media/video/vivi.c b/drivers/media/video/vivi.c
index cdef622..8275509 100644
--- a/drivers/media/video/vivi.c
+++ b/drivers/media/video/vivi.c
@@ -170,7 +170,6 @@
int users;
/* various device info */
- unsigned int resources;
struct video_device vfd;
struct vivi_dmaqueue vidq;
@@ -727,40 +726,6 @@
};
/* ------------------------------------------------------------------
- IOCTL handling
- ------------------------------------------------------------------*/
-
-
-static int res_get(struct vivi_dev *dev, struct vivi_fh *fh)
-{
- /* is it free? */
- mutex_lock(&dev->lock);
- if (dev->resources) {
- /* no, someone else uses it */
- mutex_unlock(&dev->lock);
- return 0;
- }
- /* it's free, grab it */
- dev->resources =1;
- dprintk(1,"res: get\n");
- mutex_unlock(&dev->lock);
- return 1;
-}
-
-static int res_locked(struct vivi_dev *dev)
-{
- return (dev->resources);
-}
-
-static void res_free(struct vivi_dev *dev, struct vivi_fh *fh)
-{
- mutex_lock(&dev->lock);
- dev->resources = 0;
- dprintk(1,"res: put\n");
- mutex_lock(&dev->lock);
-}
-
-/* ------------------------------------------------------------------
IOCTL vidioc handling
------------------------------------------------------------------*/
static int vidioc_querycap (struct file *file, void *priv,
@@ -913,9 +878,7 @@
if (i != fh->type)
return -EINVAL;
- if (!res_get(dev,fh))
- return -EBUSY;
- return (videobuf_streamon(&fh->vb_vidq));
+ return videobuf_streamon(&fh->vb_vidq);
}
static int vidioc_streamoff(struct file *file, void *priv, enum v4l2_buf_type i)
@@ -928,10 +891,7 @@
if (i != fh->type)
return -EINVAL;
- videobuf_streamoff(&fh->vb_vidq);
- res_free(dev,fh);
-
- return (0);
+ return videobuf_streamoff(&fh->vb_vidq);
}
static int vidioc_s_std (struct file *file, void *priv, v4l2_std_id *i)
@@ -1096,10 +1056,10 @@
vivi_read(struct file *file, char __user *data, size_t count, loff_t *ppos)
{
struct vivi_fh *fh = file->private_data;
+ struct vivi_dev *dev = fh->dev;
+ struct videobuf_queue *q = &fh->vb_vidq;
if (fh->type==V4L2_BUF_TYPE_VIDEO_CAPTURE) {
- if (res_locked(fh->dev))
- return -EBUSY;
return videobuf_read_stream(&fh->vb_vidq, data, count, ppos, 0,
file->f_flags & O_NONBLOCK);
}