> You mean call to tty_put_user(), correct? Thanks for this catch. > So what about to unlock the lock for this time? Because we need to hold > the lock while checking tty->read_cnt in the while loop condition, correct? I think you are right on that yes. Alan -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html