Isn't Wifi supposed to be off by default?

Werner Almesberger werner at
Thu Jan 15 22:08:57 CET 2009

Andy Green wrote:
> What was "normal" in suspend was between 5 - 10mA on average with GSM
> side up.  If you leave GSM side down, Allen went all the way to ~2mA.

Wow ! Okay, definitely more research is needed :-)

> | # WLAN reset
> | gpio j12 j12=0
> | 		>1
> | 					165.19mA 165.59mA 166.28mA  0.294mA
> This didn't do much, maybe a bit suspicious.

It shouldn't really do anything unless spoken to, so holding it in
reset shouldn't make much of a difference.

> | # GSM AMP
> | pmu 0x15 0x15=0
> | 		0x00
> | 					165.34mA 165.50mA 165.80mA  0.144mA
> | # GSM reset
> | gpio b5 b5=1
> | 					165.24mA 165.40mA 165.55mA  0.102mA
> Again it doesn't do much.

The GSM AMP was a no-op. I don't know if GSM reset is physically
connected on that board, so it may be a no-op as well.

> Suspend is doing stuff anyway.

Yup. I wonder why, after crudely shutting down things manually,
I'm doing better by a whole 40mA, though.

> Maybe pop the WLAN module physically to rule that out?

There's indeed something very wrong there:

# hard reset
# cut USB power
pmu 0x49=3
					239.38mA 239.69mA 240.50mA  0.369mA
# screen blanker
echo 1 >/sys/class/graphics/fb0/blank
					163.49mA 163.97mA 164.98mA  0.452mA
# suspend
echo mem >/sys/power/state
					 80.49mA  80.89mA  81.15mA  0.213mA

That's more like it. Now with the whole manual power-down:

# hard reset
					 99.13mA  99.44mA  99.71mA  0.210mA
# suspend
echo mem >/sys/power/state
					 35.61mA  35.64mA  35.67mA  0.016mA

Still high, but much better. Okay, now that WLAN module has a few
questions to answer ...

- Werner

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