force power over usb

Hans Petter Selasky hselasky at
Tue May 24 09:46:09 GMT 2005

On Monday 23 May 2005 22:58, Daniel Rucci wrote:
> >bInterfaceClass is "UICLASS_CDC_DATA".
> >
> >bInterfaceSubClass is "UISUBCLASS_DATA".
> >
> >Maybe "umodem" supports this? Try "kldload umodem" and replug your device.
> >Does it still appear as "ugen0"?
> kldload umodem does the trick! thanks, for future reference how did you
> figure that out from looking at that output?

I searched the sources. Sources can be installed from "sysinstall" if they are 
not installed already.

The interface classes are defined in "/sys/dev/usb/usb.h" (see UICLASS_XXX and 
UISUBCLASS_XXX). If you type "cat /sys/dev/usb/* |more" and press enter, then 
type "/UICLASS_CDC" and press enter. Then use the "n"-key to search forth and 
"N"-key to search back until you find something that matches your USB 

Then scroll up to find the file name:

__FBSDID("$FreeBSD: src/sys/dev/usb/umodem.c,v 1.57 2005/01/31 13:58:10 
akiyama Exp $");

Then check if there is a module that compiles this file:

cat `find /sys/modules |grep Makefile` | more

(search for "umodem.c")

If no match try kernel configuration files:

cat /sys/conf/* | more

(search for "umodem.c")

This might not be so easy, so in the future maybe something like 
"kldload /boot/kernel/usb*ko" will load all USB drivers?


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