Nut upsdev - Feb 2006 - the future libusb interface for newhidups

Peter,

You may want to have a look at the comments to Bug 164524 at 
bugzilla@redhat.com:
	https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=164524
I filed this a long while ago, because of the mess we get into when 
shutting down Linux via /etc/rc.d/init.d/halt, and the UPS device no 
longer being reachable when we want shut it down.

There seem to be some changes to libusb on the way, that expect us to 
use the /dev entry, which it is implied that that will be available at 
shutdown without the /proc/bus/usb tree. I sure hope there will be a 
proper way to correlate from the carefully identifed device by newhidups
to the proper /dev device.

Hope this will not be too messy! AG

-- 
 ----------------------------------------------------------------------
   Alfred Ganz					alfred-ganz:at:agci.com
   AG Consulting, Inc.				(203) 624-9667
   440 Prospect Street # 11
   New Haven, CT 06511
 ----------------------------------------------------------------------

I don't see this as a great problem. I simply put this in my shutdown
script, just before telling the UPS to shut off:

    if [ ! -f /proc/bus/usb/devices ]; then
        # USB has already been unmounted, but we need it to access the UPS
        echo "Re-mounting USB filesystem"
        mount -t usbfs usbfs /proc/bus/usb
    fi

I think the problem is only when using a "stock" script, so what
should really be fixed is the distribution's scripts. I don't see a
need for any libusb workaround, and there is no good way to map USB
devices to /dev entries as far as I know.

I have some instructions, by the way, on how to set up newhidups, at
http://www.mathstat.dal.ca/~selinger/ups/backups.html.
I originally wrote this before I joined the NUT developer team. 
It contains what you have to put in the shutdown script.
It might still be useful as a set of step-by-step instructions.

-- Peter

Alfred Ganz wrote:
> 
> Peter,
> 
> You may want to have a look at the comments to Bug 164524 at 
> bugzilla@redhat.com:
> 	https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=164524
> I filed this a long while ago, because of the mess we get into when 
> shutting down Linux via /etc/rc.d/init.d/halt, and the UPS device no 
> longer being reachable when we want shut it down.
> 
> There seem to be some changes to libusb on the way, that expect us to 
> use the /dev entry, which it is implied that that will be available at 
> shutdown without the /proc/bus/usb tree. I sure hope there will be a 
> proper way to correlate from the carefully identifed device by newhidups
> to the proper /dev device.
> 
> Hope this will not be too messy! AG
> 
> -- 
>  ----------------------------------------------------------------------
>    Alfred Ganz					alfred-ganz:at:agci.com
>    AG Consulting, Inc.				(203) 624-9667
>    440 Prospect Street # 11
>    New Haven, CT 06511
>  ----------------------------------------------------------------------
>