Hi, > int happened = 0; > > - spin_lock(&ud->lock); > if (ud->event != 0) > happened = 1; > - spin_unlock(&ud->lock); > > return happened; I am guessing locking was intended to protect ud->event along with happened so that (checking the value of ud->event and setting value of happened) was atomic. return ud->event != 0 ? 1 : 0; Regards. -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html