[gta02-core] Backup battery underdimensioned

Werner Almesberger werner at openmoko.org
Thu Aug 20 23:27:12 CEST 2009

Rask Ingemann Lambertsen wrote:
>    This bit on page 16 makes me worry (last six words):
> 	real-time clock will be active. The GPIOs will maintain their state.

Good point, yes. If we're in a controlled power-down state, EN_USBHOST
should be low and not draw any significant current. But if we dropped
dead with USB host enabled (which makes an excellent reason for running
out of power in the first place), then we'd leak VB_SYS/100kOhm or about
20 uA (with VB_SYS <= Vth(syspres).)

>    At least with the default ext2[1] settings, this causes two runs of
> e2fsck: The first one because the last mount time is in the future and the
> second one because the fs has gone 3000+ days without being checked.

Automatically running e2fsck is proabably a rather misguided idea in
the first place ;-)

"Why the heck does my phone freeze when I try to turn it on ?"
"It's just fsck'ing."

- Werner

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