@@ -840,13 +840,19 @@ static int uvc_ioctl_streamon(struct file *file, void *fh,
{
struct uvc_fh *handle = fh;
struct uvc_streaming *stream = handle->stream;
- int ret;
+ int ret = -EBUSY;
if (!uvc_has_privileges(handle))
return -EBUSY;
mutex_lock(&stream->mutex);
+
+ if (handle->is_streaming)
+ goto unlock;
ret = uvc_queue_streamon(&stream->queue, type);
+ handle->is_streaming = !ret;
+
+unlock:
mutex_unlock(&stream->mutex);
return ret;
@@ -857,15 +863,22 @@ static int uvc_ioctl_streamoff(struct file *file, void *fh,
{
struct uvc_fh *handle = fh;
struct uvc_streaming *stream = handle->stream;
+ int ret = 0;
if (!uvc_has_privileges(handle))
return -EBUSY;
mutex_lock(&stream->mutex);
- uvc_queue_streamoff(&stream->queue, type);
+
+ if (!handle->is_streaming)
+ goto unlock;
+ ret = uvc_queue_streamoff(&stream->queue, type);
+ handle->is_streaming = !!ret;
+
+unlock:
mutex_unlock(&stream->mutex);
- return 0;
+ return ret;
}
static int uvc_ioctl_enum_input(struct file *file, void *fh,
@@ -581,6 +581,7 @@ enum uvc_handle_state {
struct uvc_fh {
struct v4l2_fh vfh;
+ bool is_streaming;
struct uvc_video_chain *chain;
struct uvc_streaming *stream;
enum uvc_handle_state state;