Kernel 2.6.19.2: Belkin UPS on Serial vs. USB

Kernel 2.6.19.2: Belkin UPS on Serial vs. USB

[Justin Piszcz]

When I disconnect my UPS from the wall, I have to wait 15-30 seconds 
before the USB drier 'polls' this information and tells me that the UPS is 
on battery power (via knutclient or syslog via nut):

ups@p34 POWER ALERT on Fri Jan 26 12:49:29 EST 2007

With a serial connection, I would get the alerts IMMEDIATELY (0.5-1 
seconds) after disconnecting the UPS.  My new machine does not have a 
serial port built-in, only a serial header, and of course does not come 
with an included cable, so I chose to use USB.

My question is, how do I change the polling time for the USB subsystem to 
match that of the serial port, or would I not want to do that for other 
reasons?

The reason I'd like to is I am not going to see any power alerts for 
unless there is a power outage for longer than 15-30 seconds.

Justin.

Re: Kernel 2.6.19.2: Belkin UPS on Serial vs. USB

[Greg KH]

On Fri, Jan 26, 2007 at 12:54:02PM -0500, Justin Piszcz wrote:
> When I disconnect my UPS from the wall, I have to wait 15-30 seconds 
> before the USB drier 'polls' this information and tells me that the UPS is 
> on battery power (via knutclient or syslog via nut):
> 
> ups@p34 POWER ALERT on Fri Jan 26 12:49:29 EST 2007
> 
> With a serial connection, I would get the alerts IMMEDIATELY (0.5-1 
> seconds) after disconnecting the UPS.  My new machine does not have a 
> serial port built-in, only a serial header, and of course does not come 
> with an included cable, so I chose to use USB.
> 
> My question is, how do I change the polling time for the USB subsystem to 
> match that of the serial port, or would I not want to do that for other 
> reasons?
> 
> The reason I'd like to is I am not going to see any power alerts for 
> unless there is a power outage for longer than 15-30 seconds.

I think this is a userspace issue, as it's a userspace program that is
doing the polling, right?  Try asking the developers of it about this.

I think you will find it is a FAQ...

thanks,

greg k-h