On 09/11/2007 03:06 PM, Nathan Salwen wrote:
> Interestingly, when I turned isapnp=off on the command line, I got
> io 0x2f8-0x2ff
> irq 5
> but I don't know how to change this or to enable the device. I
> thought sending AUTO to the file should do that. I tried
>> echo ENABLE > resources
> but that didn't do anything.
>
> The comx driver is an interesting lead but I wonder if it is a red
> herring. When I ran sarge with the modem card physically removed, the
> COMX line also showed up in dmesg. The only difference was that
> ttyS02 is missing.
>
> modem card physically absent:
>> Serial driver version 5.05c (2001-07-08) with HUB-6 MANY_PORTS MULTIPORT SHARE_IRQ SERIAL_PCI enabled
>> ttyS00 at 0x03f8 (irq = 4) is a 16550A
>> ttyS01 at 0x02f8 (irq = 3) is a 16550A
>> COMX: driver version 0.85 (C) 1995-1999 ITConsult-Pro Co. <info@itc.hu>
>
> modem card physically present:
>> Serial driver version 5.05c (2001-07-08) with HUB-6 MANY_PORTS MULTIPORT SHARE_IRQ SERIAL_PCI enabled
>> ttyS00 at 0x03f8 (irq = 4) is a 16550A
>> ttyS01 at 0x02f8 (irq = 3) is a 16550A
>> ttyS02 at 0x03e8 (irq = 4) is a 16550A
>> COMX: driver version 0.85 (C) 1995-1999 ITConsult-Pro Co. <info@itc.hu>
>
> That is a little weird because the modem actually shows up at ttyS1.
> I guess the modem shows up at ttyS01 and the and the second internal
> UART is pushed to ttyS02. Actually, the COMX driver appears to be for
> a synchronous card and I believe my card is asynchronous as most
> modems are, so I believe that is not the driver that is actually
> handling my card. I think maybe the "Serial driver" handles my card
> but I don't really know. I have experience writing drivers but not
> with linux.
>

To me, it sounds like your modem might be normally located at ttyS2.
Communicate with your serial ports as best you can. Use ATI commands to
identify the modem(s).

>> Do you know why the device node for ttyS1 is so recent?
>
> The /dev/ttyS1 device updates its modify time every time I run
> minicom. Maybe when minicom resets the device.
>

Yes, I just noticed that here too.

>> In order for COM2 (/dev/ttyS1) to work properly, IRQ 3 and IO-PORTS
>> 0x2f8-0x2ff need to be free. Look into the /proc filesystem and ...
>
> When the card is plugged in, lenny creates space for it and removes
> the serial card from /proc/ioports
>
> proc/ioports (modem physically removed):
> ...
> 02f8-02ff : serial
> ...
>
> proc/ioports (modem physically in computer):
> ...
> 0213-0213 : ISAPnP
> ...
> 0a79-0a79 : isapnp write
> ...
>
> where the other parts are identical.
> Also, there is nothing on interrupt 3 or 4 in /proc/interrupts
> (whether the card is inserted or not).
>

Perhaps another driver is capturing the device before the serial driver
can get it.

> I have never run linux under a debugger, but my inclination would be
> to try to do that and then put a break on access to the ttyS1 io port.
> Or to the plugnplay port.
> I don't really understand the structure of the kernel so I don't
> really know where to start. I guess once the card is set up for by
> the pnp driver and the uart at that location is disabled, the kernel
> doesn't have to know whether it accessing the original uart or going
> through the modem card. Maybe all I need to do is somehow enable the
> card.
>
> Another mystery, since there is nothing at 2f8, why does ttyS1 show up?
>
> Nathan
>

I don't understand. There's something at 0x2f8 in both cases it seems.

BTW, please don't top-post on this list. It makes it harder for people
to respond.


--
To UNSUBSCRIBE, email to debian-user-REQUEST@lists.debian.org
with a subject of "unsubscribe". Trouble? Contact listmaster@lists.debian.org