[media] pwc: Allow multiple opens

Allow multiple opens of the /dev/video node so that control panel apps
can be open to-gether with streaming apps.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

3 files changed, 42 insertions, 18 deletions

diff --git a/drivers/media/video/pwc/pwc-if.c b/drivers/media/video/pwc/pwc-if.c
index b591b723f5a1..a6b5fde5c3ad 100644
--- a/drivers/media/video/pwc/pwc-if.c
+++ b/drivers/media/video/pwc/pwc-if.c
@@ -678,12 +678,6 @@ static int pwc_video_open(struct file *file)
         if (!pdev->udev)
                 return -ENODEV;
 
-        if (pdev->vopen) {
-                PWC_DEBUG_OPEN("I'm busy, someone is using the device.\n");
-                return -EBUSY;
-        }
-
-        pdev->vopen++;
         file->private_data = vdev;
         PWC_DEBUG_OPEN("<< video_open() returns 0.\n");
         return 0;
@@ -718,10 +712,12 @@ static int pwc_video_close(struct file *file)
         PWC_DEBUG_OPEN(">> video_close called(vdev = 0x%p).\n", vdev);
 
         pdev = video_get_drvdata(vdev);
-        vb2_queue_release(&pdev->vb_queue);
-        pdev->vopen--;
+        if (pdev->capt_file == file) {
+                vb2_queue_release(&pdev->vb_queue);
+                pdev->capt_file = NULL;
+        }
 
-        PWC_DEBUG_OPEN("<< video_close() vopen=%d\n", pdev->vopen);
+        PWC_DEBUG_OPEN("<< video_close()\n");
         return 0;
 }
 
@@ -734,6 +730,12 @@ static ssize_t pwc_video_read(struct file *file, char __user *buf,
         if (!pdev->udev)
                 return -ENODEV;
 
+        if (pdev->capt_file != NULL &&
+            pdev->capt_file != file)
+                return -EBUSY;
+
+        pdev->capt_file = file;
+
         return vb2_read(&pdev->vb_queue, buf, count, ppos,
                         file->f_flags & O_NONBLOCK);
 }
@@ -754,6 +756,9 @@ static int pwc_video_mmap(struct file *file, struct vm_area_struct *vma)
         struct video_device *vdev = file->private_data;
         struct pwc_device *pdev = video_get_drvdata(vdev);
 
+        if (pdev->capt_file != file)
+                return -EBUSY;
+
         return vb2_mmap(&pdev->vb_queue, vma);
 }
 
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);
 }
 
diff --git a/drivers/media/video/pwc/pwc.h b/drivers/media/video/pwc/pwc.h
index 8d82c6aac42c..d65cd14ef9f2 100644
--- a/drivers/media/video/pwc/pwc.h
+++ b/drivers/media/video/pwc/pwc.h
@@ -160,7 +160,7 @@ struct pwc_device
         char serial[30];        /* serial number (string) */
 
         /*** Video data ***/
-        int vopen;              /* flag */
+        struct file *capt_file; /* file doing video capture */
         int vendpoint;          /* video isoc endpoint */
         int vcinterface;        /* video control interface */
         int valternate;         /* alternate interface needed */