power savings will stop transfers

Chris Ball cjb at laptop.org
Wed Jan 16 13:10:14 EST 2008


Hi,

   > If you, for example, are transfering a file when the XO enters in
   > power savings mode, the transfer will halt.

For how long?  As soon as the XO hits suspend, the WLAN/EC will
assert wakeup on receipt of the next unicast packet, and then OHM
will wait another thirty seconds or more before suspending again.
Have you experienced otherwise?  The transfer should continue after
the wakeup without any disconnection.

   > (I avoided using the term 'suspend'. I believe suspend is an user
   > action, while sleep is automatic, anyway...)

Other way around; suspend is automatic and frequent, sleep is
user-invoked.

   > I don't believe this is a feature. How should we deal with it?

As above, I think this should be harmless.  If you disagree, as the
olpc-update script does, you can "touch/rm /etc/ohm/inhibit-suspend"
before/after a transfer.

Note that if the transfer uses non-trivial CPU (for example, rsync)
it should inhibit suspend automatically by virtue of the CPU use.

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


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