Index: uspace/drv/bus/usb/ohci/hc.c
===================================================================
--- uspace/drv/bus/usb/ohci/hc.c	(revision 5fe3f954848e8edeb3e7a9741c25d0f620547e10)
+++ uspace/drv/bus/usb/ohci/hc.c	(revision 0539c146a8e401db775ccf05fc1dbf2778451c9e)
@@ -304,4 +304,7 @@
 	int err;
 
+	if ((err = ohci_transfer_batch_prepare(ohci_batch)))
+		return err;
+
 	fibril_mutex_lock(&hc->guard);
 	if ((err = endpoint_activate_locked(ep, batch))) {
@@ -309,7 +312,4 @@
 		return err;
 	}
-
-	if ((err = ohci_transfer_batch_prepare(ohci_batch)))
-		return err;
 
 	ohci_transfer_batch_commit(ohci_batch);