Re: usb device not showing up

From: Alan Stern
Date: Tue Nov 04 2008 - 10:24:12 EST


On Tue, 4 Nov 2008, Norbert Preining wrote:

> Hi Alan,
>
> On Mo, 03 Nov 2008, Alan Stern wrote:
> > What happens if you leave the modem turned off until after Linux is
> > running? If it does not show up then a usbmon trace would be helpful
> > (see Documentation/usb/usbmon.txt for instructions).
>
> I can run usbmon, but I am not sure what you mean with "leave the modem
> turned off until after Linux is running".

I must have misunderstood your earlier message, where you wrote:

> Interestingly this device does disappear if I cold boot into linux.
>
> So:
> - First booting Vista, then RE-booting (not turning it off in the
> meantime) into linux gives me that device and everything works.

By "it", did you mean the laptop or the modem?

> If I start from turned off state of the laptop and boot into linux the
> device is not showing up. Is it that state you are interested in getting
> the usbmon output?

No. I'm interested in seeing the usbmon output for when the modem is
first detected by the USB subsystem. During a normal boot this will
happen before you can start usbmon.

If you can't boot with the modem off, then try this instead: Unload
ehci-hcd, uhci-hcd, and ohci-hcd, then start up usbmon (copy the 0u
file) and reload whichever driver the modem attaches to.

Alan Stern

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/