linux-kernel - kpowersave stuck at battery charging

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Date:	Wed, 2 Jan 2008 12:48:49 +0300
From:	Andrey Borzenkov <arvidjaar@...l.ru>
To:	hal@...ts.freedesktop.org
Cc:	linux-acpi@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: kpowersave stuck at battery charging

This is did not happen before; I am not sure right now what caused this (i.e. 
battery aging or some software change) nor whether this is kernel/HAL/kpowersave 
issue.

kpowersave is stuck at assuming battery is loading and at 94%. Sysfs displays 
battery state as Full:

UEVENT[1199264702.345795] 
change   /devices/LNXSYSTM:00/device:00/PNP0C0A:00/power_supply/BAT1 
(power_supply)
ACTION=change
DEVPATH=/devices/LNXSYSTM:00/device:00/PNP0C0A:00/power_supply/BAT1
SUBSYSTEM=power_supply
POWER_SUPPLY_NAME=BAT1
POWER_SUPPLY_TYPE=Battery
POWER_SUPPLY_STATUS=Full
POWER_SUPPLY_PRESENT=1
POWER_SUPPLY_TECHNOLOGY=Li-ion
POWER_SUPPLY_VOLTAGE_MIN_DESIGN=10800000
POWER_SUPPLY_VOLTAGE_NOW=11340000
POWER_SUPPLY_CURRENT_NOW=0
POWER_SUPPLY_ENERGY_FULL_DESIGN=38880000
POWER_SUPPLY_ENERGY_FULL=37530000
POWER_SUPPLY_ENERGY_NOW=35640000
POWER_SUPPLY_MODEL_NAME=XM2038P04
POWER_SUPPLY_MANUFACTURER=
SEQNUM=6472

HAL did not set (dis-)charging either:

{pts/0}% lshal -l -u /org/freedesktop/Hal/devices/computer_power_supply_0
udi = '/org/freedesktop/Hal/devices/computer_power_supply_0'
  battery.charge_level.current = 35640  (0x8b38)  (int)
  battery.charge_level.last_full = 37530  (0x929a)  (int)
  battery.charge_level.percentage = 94  (0x5e)  (int)
  battery.charge_level.rate = 0  (0x0)  (int)
  battery.current = 0  (0x0)  (int)
  battery.present = true  (bool)
  battery.rechargeable.is_charging = false  (bool)
  battery.rechargeable.is_discharging = false  (bool)
  battery.reporting.current = 35640  (0x8b38)  (int)
  battery.reporting.design = 38880  (0x97e0)  (int)
  battery.reporting.last_full = 37530  (0x929a)  (int)
  battery.reporting.technology = 'Li-ion'  (string)
  battery.reporting.unit = 'mWh'  (string)
  battery.technology = 'lithium-ion'  (string)
  battery.type = 'primary'  (string)
  battery.vendor = ''  (string)
  battery.voltage.current = 11340  (0x2c4c)  (int)
  info.capabilities = {'battery'} (string list)
  info.category = 'battery'  (string)
  info.parent = '/org/freedesktop/Hal/devices/computer'  (string)
  info.product = 'Li-ion'  (string)
  info.udi = '/org/freedesktop/Hal/devices/computer_power_supply_0'  (string)
  linux.hotplug_type = 2  (0x2)  (int)
  linux.subsystem = 'power_supply'  (string)
  linux.sysfs_path 
= '/sys/devices/LNXSYSTM:00/device:00/PNP0C0A:00/power_supply/BAT1'  (string)

Kernel 2.6.24-rc6, HAL 0.5.10, kpowersave 0.7.3.

I suspect this is kpowersave which ignores is_(dis)charging attribute and just 
compares energy_full with energy_now. According to ACPI spec, energy_full 
gives "predicted full charge capacity" - actually it is called Last Full Charge 
Capacity. At least this is what ACPI battery code implements. As such this is 
purely informational and cannot be relied upon for deciding when charging is 
complete. Actually HAL /proc/acpi/battery code did not even use this property.

So

- does ACPI battery code misuse POWER_SUPPLY_PROP_ENERGY_FULL?
- does HAL misuse .../energy_full?
- does kpowersave misuse battery.charge_level.last_full?

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