Hi Jose.
First of all, I use RedHat 5.1 and 5.2 here, so I'm somewhat peeking
in the dark. However, I can try...
> I am using slackware 3.5 installation with kernel 2.0.36 and have
> 6 serial ports available. Two serial ports are part of the
> motherboard plus an STB 4-COM serial card that makes a total of 6
> six ports. Before upgrading to linux operating system, I use OK all
> 6 serial ports under DOS/WINDOWS with the BPQ switch. Each
> individual serial port is initialized as below in the rc.local
> file.
> /sbin/setserial /dev/cua0 uart 16550 port 0x3F8 irq 4
> /sbin/setserial /dev/cua1 uart 16550 port 0x2F8 irq 3
> /sbin/setserial /dev/cua2 uart 16550 port 0x3E8 irq 10
> /sbin/setserial /dev/cua3 uart 16550 port 0x2E8 irq 5
> /sbin/setserial /dev/cua4 uart 16550 port 0x1F8 irq 11
> /sbin/setserial /dev/cua5 uart 16550 port 0x1E8 irq 12
> I look into /proc/ioports and see OK the port address taken by
> the serial ports.
Does that include the port addresses for the last two? In each case,
the range from 0x??8 through 0x??F should be included if my memory's
correct...
Also, what does /proc/interrupts have to say?
> I am having problem using the last two ports cua4 (COM5) and cua5
> (COM6). Have tried to install a TNC with kiss attach but the last
> two ports does not respond. The other first four ports works fine
> with the same TNC with kiss attach. When my linux system is
> initialized, I can see on the screen that recognizes tty00, tty01,
> tty02, tty03 but the last two ports does not show up.
The probable reason for them not showing up is that they're on
addresses that aren't in the standard port table, so I wouldnae worry
too much about that aspect of things...
> Can someone give me some hints to make the last two ports work.
Questions that pop up in my mind...
1. Are those addresses/interrupts set by jumpers or by the BIOS doing
Plug-and-Pray? If the latter, can it be disabled?
2. With the 4-port card NOT plugged in, does anything show in either
/proc/ioports or /proc/interrupts for the relevant values?
Beyond that, I'd have to refer you to the serial port expert (at
least, he wrote the serial driver), who I've cc'd this email to...
I will add that when I've had problems with the STANDARD serial ports,
it has always been because of a mismatch between the interrupt
selected and that actually in use, normally due to the BIOS playing
sillies at boot-up time, so I have to go searching to determine where
the BIOS has moved the serial ports to on this boot.
However, as Theodore assures me that probing for interrupts for the
serial ports is dangerous as the probe normally returns the wrong
interrupt number, there's little likelihood of this ever being
fixed...
Best wishes from Riley.
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* ftp://ps.cus.umist.ac.uk/pub/rhw/Linux
* http://ps.cus.umist.ac.uk/~rhw/kernel.versions.html
