[Nut-upsuser] blazer_usb MEC0002 problem Fry's Electronics (Turbo-X) [HID PDC?]

[Charles Lepple]

On Sep 8, 2016, at 9:25 AM, Vassilis Virvilis <vasvir at iit.demokritos.gr> wrote:
> 
> + failed to claim USB device: could not claim interface 0: Device or
> resource busy
> + detached kernel driver from USB device...
>  nut_usb_set_altinterface: skipped usb_set_altinterface(udev, 0)
>  HID descriptor, method 1: (9 bytes) => 09 21 00 01 00 01 22 70 02
> 
> **** device or resource busy?

This happens the first time you run a NUT driver after the USB cable is plugged in, or the system reboots. The old Linux kernel HID driver was not sufficient for reading UPS values (it could not tell the difference between an input voltage and an output voltage), so NUT detaches that driver and uses libusb instead.

You could also try adding "-x usb_set_altinterface" to the command line (or adding it to ups.conf). The lsusb output implies that the only valid setting is 0 (bAlternateSetting), but it might need to be set explicitly.

> 12) stripping, diffing -- no diffs

It might be useful to check and see if the vendor's suggested software actually works with this UPS, and if so, record some of the messages it sends.