Re: Power management (was Re: 2.3 wish: integrate pcmcia into mainstream kernel)

Werner Almesberger (almesber@lrc.di.epfl.ch)
Wed, 9 Jun 1999 14:58:26 +0200 (MET DST)


Matthew Wilcox wrote:
> Is there a mechanism for allowing a device to power itself back on when
> it receives an interrupt? This would be interesting for mobile phones,
> I imagine.

If they are able to receive interrupts while "powered down", yes. Right
now, a device is either "on" or "off", but the exact semantics are
left to the device. (E.g. it can even just acknowledge the request but
happily continue full operation.)

If a device has multiple "depths" of being powered down, one could
currently implement them as multiple devices (as far as power management
is concerned), with appropriately ordered timeouts and calls. Of course,
if this becomes a common configuration, inactivity levels need to be
supported as a general feature.

Another item for the list of potential restrictions.

- Werner

-- 
  _________________________________________________________________________
 / Werner Almesberger, DI-ICA,EPFL,CH   werner.almesberger@lrc.di.epfl.ch /
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