Suspend issues with GSM modem?

Nick Guenther kousue at
Mon Dec 17 15:53:54 CET 2007

On Dec 17, 2007 6:57 AM, "Jørgen P. Tjernø" <jorgen at> wrote:
> Hash: SHA1
> I've recently left my Neo1973 silent and lonely, due to being swamped
> with projects and school. But smoe time ago I heard there was an issue
> with the GSM modem after resuming from suspend - and this prevents the
> batterytime to getting even close to bearable.
> Is this still present? What're the specifics of the issue, and are the
> OpenMoko-guys working on it? Is it a software issue, or an actual
> hardware defect?
---use u-boot to remove the console= boot variable, makes the console
stop interfering with gsmd (since, on the hardware level, they use the
same uart)
"""The problem was that suspending would cause the modem to start
spitting out junk. and so would not respond to a modem wake up or be
able to make phone calls after resuming. The fix is a bit odd, really.
I just delete the /dev/ttySAC0 (modem) device and then create it again
right before I power up the modem. So now, that aspect of
suspending/resuming is working, at least on the one phone I have.
Well, for the first suspend anyway."""

You should note that suspending also makes gsmd stop listening to the
gsm modem, so it's either battery-life or phone. I don't know how they
are planning on fixing this, but it would have to be something similar
to ethernet wake-on-LAN.
As a temporary hack, I've got a USB charger (like, though I'm ashamed to admit
that mine is a pre-made Noma one) that I wander around with. I haven't
tested it all out in rugged conditions yet, but I imagine I could get
by for at least a day.


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