[RFC PATCH] libertas: turn radio off when down

[Sjoerd Simons]

On Wed, Nov 21, 2007 at 02:06:19AM -0500, Chris Ball wrote:
> Hi Dan,
> 
>    > Last I knew there were cases where mesh forwarding was _not_
>    > supposed to be on due to the high power drain of the 8388 when the
>    > radio was enabled, plus the airplane case.  As long as the
>    > networking core doesn't close the devices on suspend, this patch
>    > shouldn't have side-effects on mesh forwarding.
> 
> The current setup is:
> 
> suspend:  caused by idleness, radio stays on, unicast wakeups stay on

When using salut (so mesh network only) and you don't wakeup on multicast
traffic (for the groups your interested in). Then the node will drop off the
meshview after a few minutes and activities your in won't receive messages from
other nodes (and your kicked out of them after about 5 minutes of suspend)...

> sleep:  caused by lid close or power button, radio stays on, wakeups off
>
> I think it's still undecided whether sleep should leave the radio on or
> not -- we need to take power measurements now that mesh beacons can be
> disabled and see whether the power consumption is significantly reduced.
> 
>    > [1] when doing long suspends, when the resume occurs userspace will
>    > need to redo the networking setup anyway, scanning and searching
>    > for the school server or default mesh channel, because a long
>    > suspend most likely means you changed location and increases the
>    > likelihood that the networking situation around you changed as
>    > well.
> 
> Is there a dbus message OHM can pass to NM for this?  (If not, maybe
> you could mention which NM functions perform the full scan/search so
> that we can wrap them?)

And is there a signal passed to the other parts of user space before taking the
network interfaces down. In salut's case it would be nice if it would have the
chance (is a second or two) to send the necessary bye packets on both MDNS and
clique, so you can disconnect gracefully instead of the other nodes needing to
wait a few minutes to detect your network has failed.

  Sjoerd
-- 
In 1750 Issac Newton became discouraged when he fell up a flight of stairs.