Re: Devices eating too much power [was Re: Some thoughts on suspend/resume development]

[Pavel Machek <pavel-+ZI9xUNit7I@public.gmane.org>]

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Hi!

> > > > What devices is this targetted at? Video should be handled
> > > > already (or perhaps we want to power down graphics card when screen is
> > > > blanked?). Disks spin down too. IRDA ports?
> > > 
> > > - Video
> > 
> > X/dpms handles these already.
> 
> Many GPUs will have frequency scaling like processors (e.g. ATI
> Powerplay).  I don't think we currently support this.

Ugh, I did not know about this stuff. Ok.. Anyway that's X problem,
right?

> Also we don't really control display brightness.

But display brightness does not really belong here, right?

> > > Anything you might care to imagine :>
> > 
> > Well, I meant something that is not already handled. Like... what
> > power-hungry device do we fail to properly handle today?
> 
> Wireless cards could be turned off when plugged into a physical media.
> Many other devices remain on when not used (e.g. serial ports).
> Probably most of them don't take up much power, but it would be nice to
> do some experimentation and see.

I do not think wireless can be turned off when physical media is
present... but it makes sense to be user option... called ifconfig
wlan0 down. Driver should really power it down on ifconfig down.

Serial ports should not eat energy when not opened; fix it in the
driver.

What other devices do eat energy?

> I think this question really depends on architecture and hardware.
> Also, I think we'll see more power management options available to us in
> the near future.

Designing for hardware not yet available is usually bad idea.
								Pavel
-- 
People were complaining that M$ turns users into beta-testers...
...jr ghea gurz vagb qrirybcref, naq gurl frrz gb yvxr vg gung jnl!

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