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")
Signed-off-by: Ricardo Ribalda <ribalda@xxxxxxxxxxxx>
---
drivers/media/usb/uvc/uvc_ctrl.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)
diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c
index 4fe26e82e3d1..7e2fc97c9f43 100644
--- a/drivers/media/usb/uvc/uvc_ctrl.c
+++ b/drivers/media/usb/uvc/uvc_ctrl.c
@@ -1810,9 +1810,14 @@ 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_entity *entity, int rollback, struct uvc_control **err_ctrl)
{
+ unsigned int processed_ctrls = 0;
struct uvc_control *ctrl;
unsigned int i;
int ret;
@@ -1847,6 +1852,9 @@ 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),
@@ -1861,7 +1869,7 @@ static int uvc_ctrl_commit_entity(struct uvc_device *dev,
}
}
- return 0;
+ return processed_ctrls;
}
static int uvc_ctrl_find_ctrl_idx(struct uvc_entity *entity,
@@ -1910,7 +1918,7 @@ int __uvc_ctrl_commit(struct uvc_fh *handle, int rollback,
uvc_ctrl_send_events(handle, ctrls->controls, ctrls->count);
done:
mutex_unlock(&chain->ctrl_mutex);
- return ret;
+ return ret < 0 ? ret : 0;
}
int uvc_ctrl_get(struct uvc_video_chain *chain,
--
2.47.0.338.g60cca15819-goog
