1 files changed, 44 insertions, 17 deletions

diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c
index 69f9f451ab40..466f947ef440 100644
--- a/drivers/media/usb/uvc/uvc_ctrl.c
+++ b/drivers/media/usb/uvc/uvc_ctrl.c
@@ -1593,7 +1593,9 @@ static bool uvc_ctrl_xctrls_has_control(const struct v4l2_ext_control *xctrls,
 }
 
 static void uvc_ctrl_send_events(struct uvc_fh *handle,
-	const struct v4l2_ext_control *xctrls, unsigned int xctrls_count)
+				 struct uvc_entity *entity,
+				 const struct v4l2_ext_control *xctrls,
+				 unsigned int xctrls_count)
 {
 	struct uvc_control_mapping *mapping;
 	struct uvc_control *ctrl;
@@ -1604,6 +1606,9 @@ static void uvc_ctrl_send_events(struct uvc_fh *handle,
 		u32 changes = V4L2_EVENT_CTRL_CH_VALUE;
 
 		ctrl = uvc_find_control(handle->chain, xctrls[i].id, &mapping);
+		if (ctrl->entity != entity)
+			continue;
+
 		if (ctrl->info.flags & UVC_CTRL_FLAG_ASYNCHRONOUS)
 			/* Notification will be sent from an Interrupt event. */
 			continue;
@@ -1734,15 +1739,20 @@ 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;
+	int ret = 0;
 
 	if (entity == NULL)
 		return 0;
@@ -1771,8 +1781,9 @@ static int uvc_ctrl_commit_entity(struct uvc_device *dev,
 				dev->intfnum, ctrl->info.selector,
 				uvc_ctrl_data(ctrl, UVC_CTRL_DATA_CURRENT),
 				ctrl->info.size);
-		else
-			ret = 0;
+
+		if (!ret)
+			processed_ctrls++;
 
 		if (rollback || ret < 0)
 			memcpy(uvc_ctrl_data(ctrl, UVC_CTRL_DATA_CURRENT),
@@ -1781,18 +1792,25 @@ static int uvc_ctrl_commit_entity(struct uvc_device *dev,
 
 		ctrl->dirty = 0;
 
-		if (ret < 0) {
+		if (!rollback && handle && !ret &&
+		    ctrl->info.flags & UVC_CTRL_FLAG_ASYNCHRONOUS)
+			uvc_ctrl_set_handle(handle, ctrl, handle);
+
+		if (ret < 0 && !rollback) {
 			if (err_ctrl)
 				*err_ctrl = ctrl;
-			return ret;
+			/*
+			 * If we fail to set a control, we need to rollback
+			 * the next ones.
+			 */
+			rollback = 1;
 		}
-
-		if (!rollback && handle &&
-		    ctrl->info.flags & UVC_CTRL_FLAG_ASYNCHRONOUS)
-			uvc_ctrl_set_handle(handle, ctrl, handle);
 	}
 
-	return 0;
+	if (ret)
+		return ret;
+
+	return processed_ctrls;
 }
 
 static int uvc_ctrl_find_ctrl_idx(struct uvc_entity *entity,
@@ -1822,7 +1840,8 @@ int __uvc_ctrl_commit(struct uvc_fh *handle, int rollback,
 	struct uvc_video_chain *chain = handle->chain;
 	struct uvc_control *err_ctrl;
 	struct uvc_entity *entity;
-	int ret = 0;
+	int ret_out = 0;
+	int ret;
 
 	/* Find the control. */
 	list_for_each_entry(entity, &chain->entities, chain) {
@@ -1833,15 +1852,23 @@ int __uvc_ctrl_commit(struct uvc_fh *handle, int rollback,
 				ctrls->error_idx =
 					uvc_ctrl_find_ctrl_idx(entity, ctrls,
 							       err_ctrl);
-			goto done;
+			/*
+			 * When we fail to commit an entity, we need to
+			 * restore the UVC_CTRL_DATA_BACKUP for all the
+			 * controls in the other entities, otherwise our cache
+			 * and the hardware will be out of sync.
+			 */
+			rollback = 1;
+
+			ret_out = ret;
+		} else if (ret > 0 && !rollback) {
+			uvc_ctrl_send_events(handle, entity,
+					     ctrls->controls, ctrls->count);
 		}
 	}
 
-	if (!rollback)
-		uvc_ctrl_send_events(handle, ctrls->controls, ctrls->count);
-done:
 	mutex_unlock(&chain->ctrl_mutex);
-	return ret;
+	return ret_out;
 }
 
 int uvc_ctrl_get(struct uvc_video_chain *chain,