serial통신을 하기위해서
 [root@localhost root]# setserial -a /dev/ttys0
/dev/ttys0: Input/output error
[root@localhost root]# dmesg | grep tty
ttyS00 at 0x03f8 (irq = 4) is a 16550A
ttyS01 at 0x02f8 (irq = 3) is a 16550A
 [root@localhost root]# setserial /dev/ttys0 irq 4 spd_vhi
/dev/ttys0: Input/output error
 계속 input/output error만 나네요.
왜 그런지요? 부탁드립니다.