How to debug USB hardware issues

[Hans Petter Selasky]

On Friday 04 November 2011 02:01:45 Alberto Mijares wrote:
> Hi,
> 
> I have a SMS gateway with FreeBSD 8.2 RELEASE on old hardware
> (Pentium4). It has plugged a modem  Enfora SA-EL, GSM-GPRS, via USB.
> 
> The modem has been working fine for years. However, since it's plugged
> to this server, the application that manage the modem hangs every one
> or two days.
> 
> I'd like to know if there is a way to know exactly if the problem is
> the USB ports or the modem failing (because has some years now). Some
> time I have to reset the USB port (using usbconfig) and it works
> again. Tha bad thing is that the application hangs and cannot reset
> the modem (using the %RESET AT command).
> 
> Thanks in advance for your suggestions.
> 
> Regards
> 
> 
> Alberto Mijares

Hi,

What does dmesg say when this failure occurs?

Do you see the following sysctl:

sysctl hw.usb.no_cs_fail

I would start turn on debugging in the modem driver, compile kernel with 
options USB_DEBUG, and then see what is printed at the time of failure.

--HPS