[SOLVED] Input/output error accessing /dev/ttyS1 on Ubuntu 18.04
I am currently getting the error "Input/output error" whenever I try to access /dev/ttyS1 on my Up Board.
I am using Ubuntu 18.04, and installed the custom kernel by following https://wiki.up-community.org/Ubuntu#Ubuntu_18.04_installation_and_configuration
Also, my dmesg output doesn't show any mention of /dev/ttyS1, instead only this is found:
$ dmesg | grep ttyS
[ 2.377490] 00:01: ttyS0 at I/O 0x3f8 (irq = 4, base_baud = 115200) is a 16550A
[ 7.364610] 8086228A:00: ttyS4 at MMIO 0xa171b000 (irq = 39, base_baud = 2764800) is a 16550A
If I reboot to the BIOS settings screen, it looks like the pins are allocated to UART1 correctly, so it appears like everything should work.
Does anyone have any ideas on what else might need to be done to activate it?