[Pkg-utopia-maintainers] Bug#571161: Bug#571161: Bug#571161: wrong numbers just after power is unplugged

[Michael Biebl]

Hi Joey!

Am 01.03.2010 21:03, schrieb Joey Hess:
> Michael Biebl wrote:
>> could you please monitor the sysfs value directly after the unplug and send me
>> that log. I'd be interested if it is the kernel resp. hardware reporting bogus
>> values.
> 
> I looked at that and ran the acpi command also. energy_now, voltage_now and
> power_now only had small fluctuations, but current_now and power_now
> varied by up to 2 orders of magnitude! (I'll just show current_now;
> power_now values seem to be the same.)
> 
> On power:
> 
> current_now: 48019000
> 
> Battery 0: Charging, 27%, 00:24:37 until charged
> 
> Immediatly after power is unplugged, in the few seconds before g-p-m
> forced a suspend:
> 
> current_now: 969327000
> 
> Battery 0: Discharging, 27%, 00:00:29 remaining
> 
> After a suspend/resume cycle, while still on battery:
> 
> current_now: 4096000
> 
> Battery 0: Discharging, 27%, 00:54:35 remaining
> 
> Interesting that gnome-power-manager did not panic seeing this
> before, when it used hal. Does hal have a quirk mode that
> avoids the problem?

Sorry that it took so long to get back to you.
I had forwarded this bug upstream in the meantime, where we discussed if
we should employ some heuristics which handle cases like this where
current_now is ridiculuously high directly after unplug.
We haven't figured out yet, if it is just buggy hardware reporting
incorrect values, or if there is a bug in the kernel.
That said, upstream is not particularly happy to add such a quirk mode
to upower, but this seems to be a more common problem, so we need a
solution for this.

In the mean time, you can apply a workaround, which won't use
remaining-time as indicator for when to suspend/hibernate, but the
remaining percentage. For that run:

gconftool-2 -s /apps/gnome-power-manager/general/use_time_for_policy -t
bool false

or use gconf-editor.

Cheers,
Michael

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