GSM modem doesn't power off when Neo does

Kevin Dean kevin at
Tue Feb 19 20:34:30 CET 2008

I'm neither a programmer not an electrical engineer, this is only my
interpretation of what Erin said.

Bug #1003 can't be closed. The wording of the bug says "GSM is not
powered down when Linux is shut down" implies that the kernel is
capable of doing this. There are two ways to shut down the GSM modem,
the AT at POFF via gsmd which CAN NOT be brought back up without a
complete hardware restart (I'm thinking remove battery for 10 seconds,
re-insert) and which can NOT be issued if gsmd is unavailable. The
second way to shut down the gsm modem is to remove the battery. In
either case, to move from on -> off or vice versa there is a required
battery removal.

On Feb 19, 2008 12:23 PM, Shawn Rutledge <shawn.t.rutledge at> wrote:
> On Feb 19, 2008 12:57 AM, Erin Yueh <erin_yueh at> wrote:
> > Therefore, we cannot control the power status of GSM modem by PMU
> > directly. Now, we are using an AT command 'AT at POFF' to power off the
> > modem, when we shut down the device. Then, it can solov a battery
> > problem bug#1003 'GSM modem is not powered down when Linux is shut
> Well as long as that works reliably, it's the best that can be done I
> guess.  So this feature is implemented already in gsmd?

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