1 files changed, 27 insertions, 8 deletions

diff --git a/drivers/media/video/pwc/pwc-v4l.c b/drivers/media/video/pwc/pwc-v4l.c
index 8bd0a681990d..834055b71e04 100644
--- a/drivers/media/video/pwc/pwc-v4l.c
+++ b/drivers/media/video/pwc/pwc-v4l.c
@@ -284,13 +284,21 @@ static int pwc_vidioc_try_fmt(struct pwc_device *pdev, struct v4l2_format *f)
 }
 
 /* ioctl(VIDIOC_SET_FMT) */
-static int pwc_vidioc_set_fmt(struct pwc_device *pdev, struct v4l2_format *f)
+
+static int pwc_s_fmt_vid_cap(struct file *file, void *fh, struct v4l2_format *f)
 {
+        struct pwc_device *pdev = video_drvdata(file);
         int ret, fps, snapshot, compression, pixelformat;
 
         if (!pdev->udev)
                 return -ENODEV;
 
+        if (pdev->capt_file != NULL &&
+            pdev->capt_file != file)
+                return -EBUSY;
+
+        pdev->capt_file = file;
+
         ret = pwc_vidioc_try_fmt(pdev, f);
         if (ret<0)
                 return ret;
@@ -678,18 +686,17 @@ static int pwc_try_fmt_vid_cap(struct file *file, void *fh, struct v4l2_format *
         return pwc_vidioc_try_fmt(pdev, f);
 }
 
-static int pwc_s_fmt_vid_cap(struct file *file, void *fh, struct v4l2_format *f)
-{
-        struct pwc_device *pdev = video_drvdata(file);
-
-        return pwc_vidioc_set_fmt(pdev, f);
-}
-
 static int pwc_reqbufs(struct file *file, void *fh,
                        struct v4l2_requestbuffers *rb)
 {
         struct pwc_device *pdev = video_drvdata(file);
 
+        if (pdev->capt_file != NULL &&
+            pdev->capt_file != file)
+                return -EBUSY;
+
+        pdev->capt_file = file;
+
         return vb2_reqbufs(&pdev->vb_queue, rb);
 }
 
@@ -707,6 +714,9 @@ static int pwc_qbuf(struct file *file, void *fh, struct v4l2_buffer *buf)
         if (!pdev->udev)
                 return -ENODEV;
 
+        if (pdev->capt_file != file)
+                return -EBUSY;
+
         return vb2_qbuf(&pdev->vb_queue, buf);
 }
 
@@ -717,6 +727,9 @@ static int pwc_dqbuf(struct file *file, void *fh, struct v4l2_buffer *buf)
         if (!pdev->udev)
                 return -ENODEV;
 
+        if (pdev->capt_file != file)
+                return -EBUSY;
+
         return vb2_dqbuf(&pdev->vb_queue, buf, file->f_flags & O_NONBLOCK);
 }
 
@@ -727,6 +740,9 @@ static int pwc_streamon(struct file *file, void *fh, enum v4l2_buf_type i)
         if (!pdev->udev)
                 return -ENODEV;
 
+        if (pdev->capt_file != file)
+                return -EBUSY;
+
         return vb2_streamon(&pdev->vb_queue, i);
 }
 
@@ -737,6 +753,9 @@ static int pwc_streamoff(struct file *file, void *fh, enum v4l2_buf_type i)
         if (!pdev->udev)
                 return -ENODEV;
 
+        if (pdev->capt_file != file)
+                return -EBUSY;
+
         return vb2_streamoff(&pdev->vb_queue, i);
 }