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>

1 files changed, 4 insertions, 44 deletions

diff --git a/drivers/media/video/vivi.c b/drivers/media/video/vivi.c
index cdef622f6b32..82755091648b 100644
--- a/drivers/media/video/vivi.c
+++ b/drivers/media/video/vivi.c
@@ -170,7 +170,6 @@ struct vivi_dev {
         int                        users;
 
         /* various device info */
-        unsigned int               resources;
         struct video_device        vfd;
 
         struct vivi_dmaqueue       vidq;
@@ -727,40 +726,6 @@ static struct videobuf_queue_ops vivi_video_qops = {
 };
 
 /* ------------------------------------------------------------------
-        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 @@ static int vidioc_streamon(struct file *file, void *priv, enum v4l2_buf_type i)
         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 @@ static int vidioc_streamoff(struct file *file, void *priv, enum v4l2_buf_type i)
         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 @@ static ssize_t
 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);
         }