Additional information: Just checked this:
setserial -g /dev/ttyS* /dev/ttyS0, UART: unknown, Port: 0x03f8, IRQ: 4 /dev/ttyS1, UART: 16550A, Port: 0xcc00, IRQ: 17 /dev/ttyS2, UART: 16550A, Port: 0xc880, IRQ: 17 /dev/ttyS3, UART: 16550A, Port: 0x02e8, IRQ: 3 Are we opening a non exsisting port? Did an update-initrd for all kernels, reboot, errors while booting are gone. But still have 4 ttyS with only 3 physical ports. sudo dmesg| grep tty [ 0.000000] console [tty0] enabled [ 0.832371] 00:00: ttyS3 at I/O 0x2e8 (irq = 3, base_baud = 115200) is a 16550A [ 9.908812] 0000:03:00.0: ttyS0 at I/O 0xcc00 (irq = 17, base_baud = 115200) is a 16550A [ 9.929450] 0000:03:00.0: ttyS1 at I/O 0xc880 (irq = 17, base_baud = 115200) is a 16550A ls /dev/ttyS* /dev/ttyS0 /dev/ttyS1 /dev/ttyS2 /dev/ttyS3
