Wifi / off-state leakage

Werner Almesberger werner at openmoko.org
Wed Aug 20 22:15:17 CEST 2008

Joerg Reisenweber wrote:
> HUH? Please give a pointer or quote! :-(

Phew. Instead of spending the rest of the day searching through our
archives for those old problems, let me just briefly describe what

- GTA01: while powering down (PMU.NoPower), the GPIOs would "jerk",
  causing MODEM_RST to be asserted, which would in turn reset the
  modem and leave it powered on.

- HXD8: we had a GPIO (input !) to sense the power button without
  having to go through the PMU. Again, when powering down (*)
  (PMU.NoPower), this GPIO would pull down and thus make the PMU
  "think" the power button has been pressed.

(*) Not entirely sure if it was when powering up or down.

> BTW: even if this was true, it has no impact on actual GTA02-schematics,

Sorry, that wasn't clear. There will be no new trouble GPIOs in
GTA02 :-)

> OK, there are people who feel uncomfortable with a battery in *any*
> cellphone nearby, when they have some confidential talk ;-)

Well, it's also things like getting stuck in resume. While I admire
Andy's efforts in trying to patch up all these race conditions that
result from what's basically a mismatched architecture, I think he
must sometimes feel like the lone cat dropped on the planet of the
rats ...

- Werner

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