How to debug USB hardware issues

[Alberto Mijares]

>> >
>> > 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.
>>



Hi list,

I read usb_debug.c and found that I had to turn on debugging with

# sysctl hw.usb.debug=1

So, I did it.

Then, I started the application (the service is still down since my
first post in this thread) and many messages showed in dmesg and
/var/log/messages.

Tha app didn't work, so I opened one terminal with tail -f
/var/log/messages and from another terminal tried to connect to the
modem with cu -l /dev/cuaU0 -s 115200. This was the output:

Jan  6 10:19:59 kannel kernel: usbd_transfer_submit: xfer=0xc48bb968,
endpoint=0xc4b5e800, nframes=1, dir=read
Jan  6 10:19:59 kannel kernel: usb_dump_endpoint: endpoint=0xc4b5e800
edesc=0xc42f9032 isoc_next=0 toggle_next=1 bEndpointAddress=0x81
Jan  6 10:19:59 kannel kernel: usb_dump_queue: endpoint=0xc4b5e800 xfer:
Jan  6 10:19:59 kannel kernel: usbd_transfer_submit: open
Jan  6 10:19:59 kannel kernel: usbd_pipe_enter: enter
Jan  6 10:19:59 kannel kernel: usbd_pipe_start: start
Jan  6 10:20:00 kannel kernel: usbd_do_request_flags: Handle Request
function is set
Jan  6 10:20:32 kannel last message repeated 96 times
Jan  6 10:22:33 kannel last message repeated 366 times

Even so, the modem is still dead. No response.

Finally, after a while, I killed the cu process and this message showed

usbd_do_request_flags: Handle Request function is set
usbd_transfer_stop: close
usbd_transfer_done: err=USB_ERR_CANCELLED
usbd_transfer_done: err=USB_ERR_NORMAL_COMPLETION
usbd_callback_wrapper_sub: xfer=0xc48bb968 endpoint=0xc4b5e800 sts=5
alen=0, slen=2048, afrm=0, nfrm=1
usbd_do_request_flags: Handle Request function is set

u3g debug is on and no message appears.

Any hint about this? I'm about to buy a PCI->USB card, unless anyone
can say there's no problem with USB hardware. So I have to bye another
modem.

Thank you very mucho in advance.

Regards


Alberto Mijares