Hardy: new 2.6.24 'power_supply' interface confuses HAL (sees duplicate batteries)

[Dana Goyette]

When I boot the 2.6.24 kernel, gnome-power-manager shows two battery devices, one of which changes indicated value only upon switching from battery to AC (and not vice versa).

The old interface is through the ACPI 'battery' module, and shows up as product "Li-Ion". This battery . The new interface is through the 'power_supply' module, and shows up as product 'Battery Bay'.

The old battery interface disappears upon removal; the new interface indicates 0% and 'missing' instead, which is more proper behavior.

The old interface seems to no longer emit 'change' events to HAL, so the value is not updated.

In addition, this duplication of battery seems to halve gnome-power-manager's indicated wattage, but the ACPI power usage value given by powertop seems unaffected.

Thankfully, none of this affects gnome-power-manager's battery-life estimates, but I would imagine having these duplicate batteries, one of which never changes, can screw up any existing battery profiles.

[Dana Goyette (danagoyette)]

Correction: the NEW interface is the one that's not emitting 'change' events. If I make an fdi file to ignore the power_supply object with name Li-ion, I'm left with just the working battery. However, this is not a solution -- it's just a workaround. Ideally, once the lack of events is fixed there should be a way to detect duplicates, perhaps by having the power_supply sysfs class keep a link to the battery object under /proc.