If we let know our callers that we have not done anything, they will be
able to optimize their decisions.
Cc: stable@xxxxxxxxxx
Fixes: b4012002f3a3 ("[media] uvcvideo: Add support for control events")
Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
Signed-off-by: Ricardo Ribalda <ribalda@xxxxxxxxxxxx>
---
drivers/media/usb/uvc/uvc_ctrl.c | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)
diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c
index 4e58476d305e..f2484f6d21c1 100644
--- a/drivers/media/usb/uvc/uvc_ctrl.c
+++ b/drivers/media/usb/uvc/uvc_ctrl.c
@@ -1846,12 +1846,17 @@ int uvc_ctrl_begin(struct uvc_video_chain *chain)
return mutex_lock_interruptible(&chain->ctrl_mutex) ? -ERESTARTSYS : 0;
}
+/*
+ * Returns the number of uvc controls that have been correctly set, or a
+ * negative number if there has been an error.
+ */
static int uvc_ctrl_commit_entity(struct uvc_device *dev,
struct uvc_fh *handle,
struct uvc_entity *entity,
int rollback,
struct uvc_control **err_ctrl)
{
+ unsigned int processed_ctrls = 0;
struct uvc_control *ctrl;
unsigned int i;
int ret;
@@ -1886,6 +1891,9 @@ static int uvc_ctrl_commit_entity(struct uvc_device *dev,
else
ret = 0;
+ if (!ret)
+ processed_ctrls++;
+
if (rollback || ret < 0)
memcpy(uvc_ctrl_data(ctrl, UVC_CTRL_DATA_CURRENT),
uvc_ctrl_data(ctrl, UVC_CTRL_DATA_BACKUP),
@@ -1904,7 +1912,7 @@ static int uvc_ctrl_commit_entity(struct uvc_device *dev,
uvc_ctrl_set_handle(handle, ctrl, handle);
}
- return 0;
+ return processed_ctrls;
}
static int uvc_ctrl_find_ctrl_idx(struct uvc_entity *entity,
@@ -1951,6 +1959,7 @@ int __uvc_ctrl_commit(struct uvc_fh *handle, int rollback,
if (!rollback)
uvc_ctrl_send_events(handle, ctrls->controls, ctrls->count);
+ ret = 0;
done:
mutex_unlock(&chain->ctrl_mutex);
return ret;
--
2.48.1.601.g30ceb7b040-goog
