> (2) acm tty port ASYNCB_INITIALIZED flag will be cleared when > close. If acm resume callback run after ASYNCB_INITIALIZED flag > cleared, there will have no chance for delayed write to start. > That lead to acm_wb.use can't be cleared. If user space open > acm tty again and try to setd, tty will be blocked in > tty_wait_until_sent for ever. If there is data pending when the close occurs the close path should block until either the close timeout occurs or the buffer is written. This sounds more like the implementation of the ACM chars_in_buffer method is wrong and not counting the deferred bytes as unsent ? Alan -- 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