[Nut-upsuser] [UPS on Serial vs. USB] USB slow to update, serial instant.

Charles Lepple clepple at gmail.com
Sat Jan 27 16:39:23 CET 2007

On 1/27/07, Arjen de Korte <nut+users at de-korte.org> wrote:
> That depends on the driver you're using. If you're using the newhidups
> driver (which will be renamed usbhid-ups in the next release), there is
> probably not much you can do about this. Many USB protocols are *very*
> verbose and don't allow polling the status every two seconds. Therefore,
> the newhidups has a build in mechanism to only do a full status update
> every 30 seconds (if memory serves).

Unfortunately, a quick glance at this code seems to indicate that even
if the UPS sends a notification on the interrupt in pipe, NUT will
only check for that every time it does a full status update.

I think this has something to do with not wanting to spam the system
logs with timeout messages, though.

- Charles Lepple

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