[Power] Impacts of disabling Automatic Power Management

[Paul Fox]

sridhar wrote:
 > On 1 February 2012 15:43, Paul Fox <pgf at laptop.org> wrote:
 > > sridhar wrote:
 > >  > We are considering disabling Automatic Power Management because of its
 > >  > impact on collaboration and 3G connectivity.
 > >  >
 > >  > What kind of battery life can we expect from an XO-1.5 with Automatic
 > >  > Power Management disabled as opposed to enabled? I understand that
 > >  > this can vary wildly with usage, but is there an average estimate?
 > >
 > > he's on a very long plane flight, but i'll try and channel richard:
 > >
 > >    "it depends."
 > >
 > > how did i do?  :-)
 > 
 > I was trying to head that off with my "I understand that..." statement :)
 > 
 > 
 > > you're probably in as good a position to answer this as we are, since
 > > you have a better idea of your system activity load.  with automatic
 > > power management turned off, a 1.5 is good for several hours of use,
 > > where "several" is intentionally vague.  backlight on full?  wireless
 > > on?  continuous cpu activity?  etc.
 > >
 > > would it help to disable automatic power management only when specific
 > > Activities are running?  only when certain kinds of collaboration are
 > > in effect?  only when certain drivers are active?
 > 
 > We've been thinking of doing this for when 3G connections are active
 > [1]. It might be interesting to also tie this into Sugar's
 > collaboration mechanism and disable power management when a session is
 > active.

in http://dev.laptop.org/ticket/10708 i suggested adding the 3G modem's
USB vendor/product ID to /etc/powerd/flags/usb-inhibits.  this would
stop automatic power management while the device is present.  would that
help?

paul

 > 
 > Sridhar
 > 
 > 
 > [1] https://dev.laptop.org.au/issues/1029
 > 
 > 
 > 
 > Sridhar Dhanapalan
 > Engineering Manager
 > One Laptop per Child Australia

=---------------------
 paul fox, pgf at laptop.org