Battery charging state preserved over hibernate

[Andrew Benham]

Binary package hint: acpi

I'm using Ubuntu 10.10 on a Sony Vaio EE2M1E laptop. Suspend and hibernate work fine out of the box, with one exception:

The battery charging/discharging/charged state and the on-line/off-line state of the AC adapter are both erroneously preserved when coming out of hibernate. This is a problem when the new state is different from the state when the laptop entered hibernate.

For example, the laptop is running on battery power and the battery is running very low. I hibernate the laptop, find the AC adapter, plug the AC adapter in (so the battery is now charging), and bring the laptop out of hibernate. /proc/acpi/battery/BAT1/state tells me the battery is discharging, and /proc/acpi/ac_adapter/ACAD/state tells me the AC adapter is off-line. Both these states are wrong. This erroneous data is carried all the way up to the Gnome Power Manager icon. The battery is discharging, but the time left until the battery is empty is increasing.

Second example, charge the laptop completely, unplug the AC adapter, then hibernate. When the laptop is brought out of hibernate /proc/acpi/battery/BAT1/state tells me the battery is charged - this state is wrong. The laptop will run happily reporting the battery as fully charged although the battery is discharging.

This problem isn't terribly important because I can plug or unplug the AC adapter with the laptop running to update the current states of the battery and AC adapter. A software workaround would be an acceptable solution.

This problem only occurs with hibernate - coming out of suspend behaves correctly.

acpid: 1.0.10-5ubuntu4
`uname -a`: Linux vaio 2.6.35-22-generic #35-Ubuntu SMP Sat Oct 16 20:36:48 UTC 2010 i686 GNU/Linux