Re: Trouble accessing USB modems on NetBSD 8.1 x86_64

[Jeffrey Walton <noloader%gmail.com@localhost>]

On Sun, Nov 24, 2019 at 11:52 PM Michael van Elst <mlelstv%serpens.de@localhost> wrote:
>
> noloader%gmail.com@localhost (Jeffrey Walton) writes:
>
> >umodem0 at uhub1 port 1 configuration 2 interface 0
> >umodem0: U.S.Robotics (0xbaf) USB Modem (0x303), rev 2.00/2.00, addr
> >2, iclass 2/2
> >umodem0: data interface 1, has CM over data, has break
> >umodem0: status change notification available
> >ucom0 at umodem0
> >ugen0 at uhub0 port 1
> >ugen0: Conexant (0x572) USB Modem (0x1340), rev 1.10/1.00, addr 2
>
> >I visited the umodem (4) man page [0]. I tried opening the modems
> >using /dev/ucom0, /dev/umodem0, ucom0 and umodem0. All of them result
> >in "No such file or directory." I also tried opening /dev/ugen0 anad
> >ugen0 with the same result.
>
> ucom<n> is associated with /dev/ttyU<n> and /dev/dtyU<n>.
>
> So in your case try /dev/dtyU0.

OK, thanks. I was able to connect to the USR using /dev/dtyU0 after rebooting.

> The Conexant device is a "soft modem", it cannot be used like a standard
> USB modem or serial port. You would need a driver that emulates a tty
> interface but uses a proprietary protocol when talking to the device.
> Since NetBSD lacks such a driver, the device attaches as 'ugen', so you
> could do low-level USB operations yourself via /dev/ugen0.00 (.. ugen0.15)
> if you knew that proprietary protocol.

Ah, thanks. That explains the Conexant problems. I'll swap-in a
MultiTech modem for testing.

One thing I noticed... I have a modem-dump program that dumps a
running config. It prints S0 - S36, ATI0 - ATI10, and some settings
like +FCLASS, +PCW and +VCID.

I noticed the (vm) machine reboots about two-thirds of the way through
the modem-dump program. Bright green text is displayed and then a
reboot. I can't read fast enough to see what is going on...

I tried to use crash(8) after the reboot but it did not find a dump.
(Should it find a kernel crash dump when started?) Here's the man page
but I am not fluent in NetBSD:
https://netbsd.gw.com/cgi-bin/man-cgi?crash++NetBSD-current .

If you tell me how, I can probably make a core file available if
someone is interested in looking at it.

Jeff