Re: UART not generating MSR-change (or any) interrupt

From: "Ulrich Hertlein" <redacted>

UART of the requested port. For I/O base and IRQ 'setserial' reports the
expected standard values (COM1=0x3f8,IRQ=4 COM2=0x2f8,IRQ=3 ...) and I'm

[snip]

IRQ=3,COM2.

Motherboard serial ports are generally still handled as ISA devices;
they cannot share interrupts. I suspect that your uart is generating
interrupts that are getting caught by the serial driver, which is
ignoring them since it doesn't know about your hardware. Try
# setserial uart none /dev/ttyS1
(synatx may be off slightly), to remove the conflict.

..Stu