power management

[Chris Ball]

Hi Jens,

   > Hi, I'd love to help out with the power management and
   > suspend/resume parts, but so far I'm having trouble finding out
   > what the status of it is, goals, directions, etc. Did I miss a wiki
   > page on this? If not, anyone care to outline the current problems
   > that need tackling?

Almost everything's happening on IRC at the moment.  We're still working
on having our display controller resume properly -- we have a novel
resume strategy which is that the display controller has RAM to keep 
the screen displaying while the CPU is asleep, so that we can go to S3
anytime the user isn't typing or running something on the CPU.  The
wireless stays on (forwarding packets) in S3, too.  

We aren't using ACPI, because we want as much control over our 
suspend/resume time as possible, and because we already know
everything about the hardware -- it's no use being able to go
to sleep between keystrokes if it takes so long to do so that 
the user realises it's happening.  I'm sure there'll be work both
specific to OLPC and generic to Linux involved in getting suspend
and resume as fast as they can be.

Hope that makes sense as a set of goals; once we have the base 
drivers resuming as well as the kernel, I think it'll be time to 
provide documentation on the wiki for easy steps to upgrade to a 
build with our kernel patches.  That should happen shortly.

Thanks!

- Chris.
-- 
Chris Ball   <cjb at laptop.org>