Quick followup.
I reinstalled the modem to COM5 as described near the end below
(in the "observations/questions" section), and no joy.
Reading the setserial manpage a little closer (something I
probably should have done sooner), I see that the command doesn't
like IRQ9 and indeed maps it to IRQ2. On first glance that
suggests that all the stuff I tried below should work, since
IRQ2 and IRQ9 are theoretically the same thing, but obviously
it doesn't....
Maybe I should try putting the card in a different slot, and
seeing what IRQ the BIOS assigns to it. Or maybe just leave it
where it is, and assign various IRQs to it by disabling the
autoassign in the BIOS, and see whether Linux will boot. I
have a friend with a nearly identical machine who uses IRQ12
for his modem, maybe I should try that.
Any other ideas? TIA....
> Sorry this is kind of long, but I wanted to get all the info
> in....
>
> System: Asus A7v133 mobo / Athlon 1.2G
> OS: dual-boot WinMe / Mandrake 7.2
> Modem: Multitech MT5634ZPX-PCI
>
> Modem is claimed to NOT be a winmodem, and there are Linux
> installation instructions in the user's manual. Manufacturer
> also has RedHat RPMs at his FTP site, but does not refer to
> these in the manual.
>
> Modem works fine under Windows. Device Manager lists it as
> being at COM3, IRQ9, I/O as follows:
>
> A400-A4FF
> A000-A0FF
> 9800-9807
>
> The modem is in PCI slot 4 (I have 5 PCI and 1 AGP slots).
>
> Per manufacturer's Linux installation instructions, I examined
> /proc/pci for modem info. Parameters are exactly as those
> listed by Windows Device Manager (see above), except of course
> there is no COM port given.
>
> I thought about including the /proc/pci file here, but because of
> its size I posted it at http://mshaw.topcities.com/proc_pci.txt
> instead. I note that it indicates that IRQ9 is shared by the USB
> controller, and I seem to remember something about Linux not
> playing well with USB yet....
>
> So, continuing with manufacturer's instructions, I obviously
> want to configure /dev/ttyS2. First I check it, as root:
>
> # setserial /dev/ttyS2
>
> Output indicates UART unknown / port 0x03e8 / IRQ4.
>
> So now I reconfigure it:
>
> # setserial /dev/ttyS2 uart 16550A port 0xa400 irq 9
>
> Checking again w/ 'setserial /dev/ttyS2' indicates that my settings
> have taken hold EXCEPT that it's on IRQ2.
>
> Not knowing what else to do, I proceed anyway. I want to use
> minicom to test the modem, so:
>
> # ln -s /dev/ttyS2 /dev/modem
> # chmod 666 /dev/ttyS2
> # minicom -s (and save config file)
>
> Then, as a normal user:
>
> % minicom
> % minicom: cannot open /dev/modem; device or resource busy
>
> Hrmph.
>
> I get the idea that when the manual told me to set the port to
> the "first" I/O address found in /proc/pci, it might've meant
> "first in the memory map," not "first listed." So I re-issue
> my setserial command:
>
> # setserial /dev/ttyS2 uart 16550A port 0x9800 irq 9
>
> and try again. Same result, only now minicom tells me that there's
> "no such file or directory" as /dev/modem, which I know isn't true
> via 'ls' and 'file'.
>
> Setting things back to their original configuration each time, I
> try all of the above with ttySn, for n == [1,3,4,31]. The results
> are always the same, and each time the port is stuck on IRQ2.
> (But when I set things BACK, e.g. restore /dev/ttyS2 to IRQ4, that
> seems to work.)
>
> I remembered that a guy here at work told me that COM1 and COM3
> work best with IRQ4, and COM2 and COM4 work best with IRQ3. So
> I change the BIOS setting for PCI slot 4/5 from autoconfigure to
> IRQ4. Now Windows indicates that everything is as it was before,
> except the modem's now on IRQ4. And the modem works fine. But
> Linux won't boot -- it freezes on that blue page with all the boot
> steps and the penguin in the upper-left-hand corner. I dimly recall
> hearing/reading something about how Mandrake checks h/w configurations
> at install time, but not afterwards, so maybe this is why....
>
> Double hrmph.
>
> So I set things back to the way they were and started working on
> this plea for help. :)
>
> Observations/questions:
>
> - The original Windows installation routine put the modem
> on COM5 (I forget which IRQ). Now that I'm reading the
> documentation a little closer than I was at the time, I
> find that this is normal. I used one of the .exe utilities
> that came on the installation CD to change it to COM4
> because the Mandrake modem-installation GUI -- which I'm no
> longer using, obviously -- only listed COM1 through COM4.
> (It didn't work there either; that's why I changed it again
> to COM3 and started taking better notes.) I wonder what
> would happen if I just reinstalled the modem to COM5 and went
> through the above sequence again?
>
> - The /proc/pci gives I/O addresses as (e.g.) 0xa400 [0xa401].
> What is the significance of the [0xa401]?
>
> - I wonder what would happen if I changed the BIOS again to
> force the modem to be on IRQ4, then reinstalled Linux?
> Obviously I'm going to leave this option till later -- like,
> last -- in the troubleshooting process....
>
> - The main thing that concerns me is the apparent inability of
> setserial to control the IRQ. No matter what I try to set it
> to, it seems to get set to 2 (assuming I can trust the output),
> unless I set it back to what it was previously. Am I not using
> the command correctly?
>
> Anyway, thanks for reading this far. Any comments? Thanks!
>
> --
> Mark Shaw
>
