Wireless interface power

Javier Cardona javier at cozybit.com
Thu Apr 19 22:26:30 EDT 2007

Forwarded to the list.  Maybe someone else has an answer for this:

---------- Forwarded message ----------
From: Andrey Yurovsky <andrey at cozybit.com>
Date: Apr 18, 2007 9:33 PM
Subject: Re: msh0 interface behavior change proposal
To: John Watlington <wad at laptop.org>, Javier Cardona <javier at cozybit.com>

Hi John.  We tried suspending to RAM with the suspend6 (I think) and
stock firmwares on build 384 and power was definitely cut:
1) attached debugger to WLAN module
2) # echo m > /sys/power/state
3) system suspends, [JTAG] debugger is no longer attached to the WLAN
module's processor

I checked /sys/power/state and it has 'mem' and 'disk' options, so I
assume 'mem' is right.  Is there something I'm doing wrong or is there
some other way to have it suspend but keep the power to the WLAN
module on?  Thanks,


On 4/18/07, John Watlington <wad at laptop.org> wrote:
> Javier,
>     Power to the WLAN is NOT cut during suspend.  My explanation of
> power domains
> needs clarification.   The WLAN is powered almost continuously
> (possibly even when
> the laptop is powered off).   Hence it is in the "green" domain, not
> the yellow domain.
> (...)
> wad
> On Apr 18, 2007, at 10:07 PM, Javier Cardona wrote:
> > All,
> >
> > (...)
> > PS.  Unfortunately the wlan power is cut off when the laptop is
> > suspended.  Otherwise we we would have basic autonomous mode up and
> > running by now (
> > http://wiki.laptop.org/go/
> > Hardware_Power_Domains#Powered_in_Suspend_.28Yellow.29
> > ).
> >

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