AnyDATA ADU-500A USB-modem and a lot of "ubsa_cfg_request" errors

[Alexey Markov]

Hello, Hans!
On November, 05 2009 at 15:59 you wrote to freebsd-usb at freebsd.org:

 ??>> except that I got a lot of such messages on console when I run ppp:
 ??>> 
 ??>> ubsa_cfg_request:371: device request failed, err=USB_ERROR_STALLED
 ??>> 
 ??>> I really want to work it out, and I have some spare time for
 ??>> experiments, but haven't any experience of debuging kernel drivers.
 ??>> Can anybody give me a clue to solve this little problem?

 HPS> Did you look in the source code:
 HPS> /sys/dev/usb/serial/ubsa.c

Yes, of course! Line #317 belongs to ubsa_cfg_request(), which just calls
another function, ucom_cfg_do_request(), with some parameters. But this
function is called several times in the code, so I've changed code of
ubsa_cfg_request() function to see, which config requests are failed:

DPRINTFN(0, "device request failed, err=%s, index=%d, value=%d "...

I have got a lot of messages like this one:

ubsa_cfg_request:371: device request failed, err=USB_ERROR_STALLED,
index=10, value=1 (ignored)

where index/value pairs sequence is:

10/1, 11/1, 12/0, 0/24, 3/0, 2/3, 1/0, 16/384, 0/2, 3/0 and so forth.

It seems, that driver tried to set some config parameters like DTR, RTS,
BAUDRATE etc, and failed. But after all, modem is working (maybe, with
non-optimal settings or default settings).

So, I need an advice: what can I do to find the cause of failed config
requests?

-- 
WBR, Alexey Markov.