[CentOS] Need help configuring additional serial ports

Fri Jun 23 18:40:36 UTC 2006
William L. Maltby <BillsCentOS at triad.rr.com>

On Fri, 2006-06-23 at 13:46 -0400, Alfred von Campe wrote:
> I installed a 2 port serial PCI card on a system running CentOS 4.3,  
> but I can't get the additional serial ports to work.  The card I used  
> is from StarTech (http://www.startech.com/Product/ItemDetail.aspx? 
> productid=PCI2S550&c=US).  When it is detected by kudzu, it shows up  
> as a "NetMos Technologies PCI 9835 Multi I/O Controller".  I've  
> included the output of "lspci" and "cat /proc/pci" below.
> 
> The (very sparse) instructions for Linux support for this card state  
> that you should look for the string "serial port x" in the contents  
> of /proc/pci, and then use that information with the setserial  
> command to configure the port as follows:
> 
>      # setserial /dev/ttyS2 port 0xc000 uart 16550 irq 11 baud_base  
> 115200
> 
> The problem is that I can't find the equivalent of the "0xc000" and  
> the IRQ on my system in the contents of /proc/pci.  Here is what the  
> built-in, working serial port looks like:
> 
>      # setserial -a /dev/ttyS0
>      /dev/ttyS0, Line 0, UART: 16550A, Port: 0x03f8, IRQ: 4
>          Baud_base: 115200, close_delay: 500, divisor: 0
>          closing_wait: 30000
>          Flags: spd_normal skip_test auto_irq
> 
> Any ideas how to get these serial ports working?

First look at /var/log/dmesg and see if it's found there. If it is,
should should see some accurate numbers. Also /var/log/messages might
have something.

A reported IRQ and startmem address should be shown and might not match
the instructions, which a very likely examples only. Hopefully those
will give clues you need.

If that fails, watch the screen at reboot (with settings that slow
things down) and observe the ESCD display that lists the ports,
controllers, etc. You might see a real address and IRQ there.

Make sure there is a real /dev/ttyS2 in /dev. This presumes that it is
the 3rd serial port. 2nd would be ttyS1. It must have the right minor
device for the nth serial card. That is usually (nth - 1) + some-magic.

Results like 64, 65, 66, ... for minor device. And maybe ttyS* is not
right for this card? It's been so long since I read up on that stuff...
S means wait for carrier detect before allowing open? This is, "blocking
read". Others don't need that, "non-blocking read". Like a dumb terminal
hooked up with a badly made null-modem cable or adapter.

> 
> Thanks,
> Alfred
> <snip>

HTH
-- 
Bill
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 189 bytes
Desc: This is a digitally signed message part
URL: <http://lists.centos.org/pipermail/centos/attachments/20060623/ca84ffa9/attachment-0005.sig>