[Nut-upsuser] Usbhip-ups going wild

[Charles Lepple]

On Aug 11, 2009, at 4:37 AM, Antoine Gatineau wrote:

> On the machine connected to a MGE Evolutipn 1250, I got this message  
> during
> the night :
> Aug 10 23:44:17 localhost kernel: hub 3-0:1.0: port 2 disabled by hub
> (EMI?), re-enabling...
> Aug 10 23:44:17 localhost kernel: usb 3-2: USB disconnect, address 14
> Aug 10 23:44:26 localhost kernel: usb 3-2: new low speed USB device  
> using
> address 16
>
> It doesn't really bother me because it is reconnected in 10 seconds  
> but
> isn't there some issue here?
> It is the kernel that disconnects the device but I wonder why...

The kernel is disconnecting it, but that is based on a signal from the  
root hub hardware (probably on your motherboard).

The EMI is likely caused by insufficient isolation between the USB  
hardware and the power switching circuitry in the UPS.