2.6.20-16 kernel breaks acpi battery

[keneida]

After kernel update from 2.6.20-15 to -16 my battery is not visible for the system. It reports that computer is running on AC power only withou battery.
My computer is benq joybook s53 (some info about hw is at http://www.capponcino.it/alessio/linux_on_joybook-S53/index.html)
Untill this update everything worked.

[eis (launchpad-eiselin)]

This happened to me too. No battery information what so ever after the update to kernel 2.6.20-16. When I boot into 2.6.20-15 everything works fine. I have a 'smart battery system' in my Acer Aspire 1680.

[Ben Van Aerde (benvanaerde)]

I'm having the same problem here with my Acer Travelmate 4001WLMi.
the command "acpi" doesn't have any output at all, so for some reason the battery is not recognised.

In the attachment you can see the Gnome Power Manger icon that is shown, with "Computer is running on AC power" tooltip. Normally a different icon is shown.

[Walter Wunsch (wwunsch)]

same as me with my acer extensa3000 running feisty (upgraded from edgy) after update from 2.6.20.15 to ~.16.
with 2.6.2.15 all is fine!
at boottime the system hangs about 30 sec. by loading acpi
i tried different things:
looking at rc2.d that acpi is starting before dbus: o.k.
looking if acpi is running: o.k.
restarting dbus: no effect
cat /proc/acpi/battery/*/state: not there!
depmod -e: no effect!
rmmod battery, modeprobe battery: no effect!

on my ibm a22p (feisty clear install) after update from 2.6.20.15 to ~.16 it's o.k.
after rmmod battery: same effect as on my acer!
after modprobe battery: works fine again!
at boottime no timeleak by loading acpi!

[Walter Wunsch (wwunsch)]

i've forgotten: when adding the batteryicon to the gnomepanel on my acer, info shows "hal-backend not used"
on my ibm "hal-backend used"

[youshotwhointhatwhatnow (moloney-brendan)]

I am having the exact same issue on my Acer Aspire 1680 and Feisty Fawn. If I boot to the old kernel (2.6.20-15) everything works fine, but if I boot to the newer kernel (2.6.20-16) then my /proc/acpi/battery directory is empty and gnome-power-manager says there is no battery.

[diaboflo (ubuntu-diaboflo)]

Same in Kubuntu on one more Acer TravelMate 4001 WLMi. Seems to be Acer-specific. but why did it work with the old kernel?

[youshotwhointhatwhatnow (moloney-brendan)]

It is most likely a problem with laptops who use a "smart battery system" like all Acers. The orignal poster has a Benq laptop.

[youshotwhointhatwhatnow (moloney-brendan)]

This is a duplicate of bug 117773.

https://bugs.launchpad.net/ubuntu/+source/linux-source-2.6.20/+bug/117773