/dev/cuau* ports hang after a while

[Timo Rikkonen]

Hi,

With 'hang' I mean the stop of the data flow. There's a measurement device connected to the serial port, which sends every minute data to our computer. The line is never closed but after a while data is no longer received.

Tried already building kernel without uart, and the ports really came out as sio's, but the devicefile numbering was still odd, now they were /dev/cuad0-3, the cuad0 used to be the motherboard-serialport devicefile (is now /dev/cuad4) and for this reason (perhaps?) cuad0 does not work.

Hardware is identical, only changed thing is the BSD-version.

Regards,
Timo

-----Original Message-----
From: Ulrich Spörlein [mailto:uspoerlein at gmail.com] 
Sent: 29. tammikuuta 2009 22:24
To: Timo Rikkonen
Cc: freebsd-stable at freebsd.org; Ed Schouten; Marcel Moolenaar
Subject: Re: /dev/cuau* ports hang after a while

On Mon, 26.01.2009 at 15:00:11 +0200, Timo Rikkonen wrote:
> Hi,
> 
> We are using "VScom PCI-200L" and "Moxa Technologies, C168H/PCI"
> -cards for serial ports. After installing 7.0 the ports or the
> connection to the port hang after a while. A "while" could be
> half-a-day or 10 minutes. There is no error message to be seen
> anywhere.

What exactly do you mean by "hang"? I discovered something odd, when I
upgraded my 6.3 box to 7.1, namely, that the serial console (no matter
if it's sio or uart) will not echo anything, once I "hang up" the line
for the first time.

To make this clear:

I reboot with serial console attached, I see kernel console, then
getty/login prompt. I can login fine, and do stuff. Once I exit tip(1)
on the terminal, the port is "mostly" dead on the server. I say mostly,
because I can still blindly enter the root login and confirm via
separate ssh login, that I'm logged in to the machine on the serial
getty port.

So it seems to me, whenever sio/uart receive the first device close
event, they get b0rked and receive only input, but can no longer send
any output.

> Not all ports hang at the same time, it could be just one or two of
> them. Earlier versions (6.2-RELEASE) work just fine. The ports have
> different devicenames after 7.0, in 6.2 they were /dev/cuad4-7, now
> they are /dev/cuau0-3 (uart?)

Try rebuilding a kernel without uart and see if they come up as sio
ports again (and work?)

> We have over 20 installations, now two of them have been upgraded to 7.0 with mentioned side effects.

Is this identical hardware? 

Cheers,
Ulrich Spörlein
-- 
None are more hopelessly enslaved than those who falsely believe they are free
-- Johann Wolfgang von Goethe