[Nut-upsuser] Working platform with FreeBSD + USB + MGE Ellipse(usbhid-ups)

[Michelle Dupuis]

> -----Original Message-----
> From: 
> nut-upsuser-bounces+support=ocg.ca at lists.alioth.debian.org 
> [mailto:nut-upsuser-bounces+support=ocg.ca at lists.alioth.debian
> .org] On Behalf Of herve-nut at mindstep.com
> Sent: Monday, January 07, 2008 5:21 AM
> To: nut-upsuser at lists.alioth.debian.org
> Subject: [Nut-upsuser] Working platform with FreeBSD + USB + 
> MGE Ellipse(usbhid-ups)
> 
> Hi,
> 
> I've have had some difficulties to run NUT on freebsd, but I 
> finally managed to have something that work reliably enough. 
> For those who may be interested, here is what I did.
> 
> Os: FreeBSD 6.2-RELEASE-p7, nut: 2.2.0, libusb: 0.1.12
> 
> First, I had to patch libusb with the changes submitted by 
> Nevil Thatcher in the nutups forum in may 2006. Without this 
> change, nothing works.
> (http://lists.alioth.debian.org/pipermail/nut-upsuser/2006-May
> /000992.html)
> 
> At this point, I had something that more or less works, but 
> the USB connection drops occasionaly for some reasons, and 
> won't recover. I did not trace it enough to see what happens, 
> but it seems that something occurs in freebsd kernel layers 
> that bubbles to the reading process as an "IO error" (errno=EIO=5).
> 
> The reason why it does not recover is still somehow obscurs 
> to me, but I'm pretty much convinced it is related to the way 
> the libusb layer deal with re-initialization. I'm new to this 
> library, but it looks like the function usb_init(); (and 
> friends) is not designed to run more than once in the process 
> lifetime.
> 
> Instead of "fixing" those parts, which would have taken a lot 
> of time, I used another approach: I implemented a "respawn" 
> option for the driver process, which automatically restarts 
> the process when it exits. I also did a few changes in the 
> driver code so that it exits whenever a USB connection problem occurs.
> 
> At this point, I have something that works reliably enough. 
> Using my UPS (MGE ellipse 750), I see about 20 losses of 
> connection per day, and the system takes between 5 and 10s to recover.
> 
> I did another change which is more cosmetic than anything 
> else. In order to keep short reconnections silents (in my 
> logging system), I added a grace period that delays the 
> COMMBAD event. If the system recovers before this period, no 
> event is issued.
> 
> - Hervé
> 
> 
>