I need to expand my linux (slackware) PC with multiserial card.
When I first use the set serial command it allows me to set it up.
After that I find out that I probably use wrong address.

The command was:

setserial /dev/ttyS2 port 0xbc00 UART 16550A irq 3 Baud_base 115200

The wrong address was 0x03e8.

I fallowed the instructions from the manufacturer, and it tells to check the PCI card with command:

more /proc/pci

I get:

Bus 1, device 2, function 0:
Serial controller: Timedia Technology Co Ltd PCI2S550 (Dual 16550 UART) (rev 1).
IRQ 3.
I/O at 0xbc00 [0xbc1f].

So I think that the I/O address should be 0xbc00 but I cannot reset the serial port with setserial.

I get this error:
Cannot set serial info: Address already in use

How can I free the serial terminal /dev/ttyS2 again?

I have new results.
I have use the setserial command the wrong way the second time.

setserial /dev/ttyS2 port 0xbc00 UART 16550A irq 3 Baud_base 115200

Now I use it with only the port 0xbc00 parameter, and it worked it changed this parameter.

But I am still not sure about this parameter. Are the information correct from the "more /proc/pci" command? The port parameter.

Bus 1, device 2, function 0:
Serial controller: Timedia Technology Co Ltd PCI2S550 (Dual 16550 UART) (rev 1).
IRQ 3.
I/O at 0xbc00 [0xbc1f].