[Q] PCI card with serial ports giving trouble

[Erich.Waelde@t-online.de]

Hello all,

I have no good idea where to start, so I opted for this
list (after google and yahoo). Please CC me on any replies,
as I'm not on the list.

I use a PCI card with 4 serial (and 1 parallel) ports, namely 
an EXSYS 16950/954 card. The card is recognized by the kernel,
the ports (and whatever I hook onto the cables) can be accessed
ok --- at first sight.

I hook an embedded system's console to one of the cards ports,
and run minicom (or a script) to access the port. The embedded
system will react and give me a shell prompt. After some time
(minutes, but irregular) the following symptoms appear:

The screen is scrolling, listing text like
  ATZ: command  not found
or similar. Interestingly, if I had "date" as the last command, say,
the command seems to be rerun (the time changes). I also see
commands spawning processes being rerun resulting in several
new processes.

It seems to me as if the I/O-buffer on the card (128byte) is being sent
to the embedded system repeatedly.

I have moved the card from an i386 box to a powerpc box (excluding
ACPI as the culprit), I have exchanged minicom with a perl script, but 
the problem persists.

The problem goes away if I use the builtin serial port.
It could be a silly config problem, but I have no clue where to
look for what.

Any pointers are well appreciated!

Thanks in advance!
Erich

PS I'm running Debian Linux, 2.6.6 or 2.4.26 kernels on the ``host''
side
and uClinux on the embedded side.