On Sat, Feb 24, 2018 at 10:20:15AM +0100, Laszlo Toth wrote:
> With a degraded battery, full_charge_capacity can be less
> than design_capacity, however it's not sure that capacity_now's
> max will follow.
>
> Example from an affected machine:
> /sys/class/power_supply/BAT0/charge_full -> 4290000
> /sys/class/power_supply/BAT0/charge_full_design -> 5900000
> /sys/class/power_supply/BAT0/charge_now -> 5900000
> /sys/class/power_supply/BAT0/capacity -> 137
>
> The battery is a degraded one with a full charge, and
> charge_now is the value of charge_full_design instead of
> charge_full.
>
> Added a new quirk to test and correct this, and
> a new function to check if the battery is a degraded one
> or not. This keeps the possibility to be over 100 if
> it's really the case.
>
> Signed-off-by: Laszlo Toth <laszlth@xxxxxxxxx>
> ---
> Changes in v2:
> - renamed quirk
> - simplified acpi_battery_is_degraded()
> - removed line break at set_bit()
>
> drivers/acpi/battery.c | 27 +++++++++++++++++++++++++++
> 1 file changed, 27 insertions(+)
>
> diff --git a/drivers/acpi/battery.c b/drivers/acpi/battery.c
> index 7128488..4aa15ab 100644
> --- a/drivers/acpi/battery.c
> +++ b/drivers/acpi/battery.c
> @@ -116,6 +116,10 @@ enum {
> post-1.29 BIOS), but as of Nov. 2012, no such update is
> available for the 2010 models. */
> ACPI_BATTERY_QUIRK_THINKPAD_MAH,
> + /* for batteries reporting current capacity with design capacity
> + * on a full charge, but showing degradation in full charge cap.
> + */
> + ACPI_BATTERY_QUIRK_DEGRADED_FULL_CHARGE,
> };
>
> struct acpi_battery {
> @@ -201,6 +205,12 @@ static int acpi_battery_is_charged(struct acpi_battery *battery)
> return 0;
> }
>
> +static bool acpi_battery_is_degraded(struct acpi_battery *battery)
> +{
> + return battery->full_charge_capacity && battery->design_capacity &&
> + battery->full_charge_capacity < battery->design_capacity;
> +}
> +
> static int acpi_battery_get_property(struct power_supply *psy,
> enum power_supply_property psp,
> union power_supply_propval *val)
> @@ -475,6 +485,10 @@ static int extract_battery_info(const int use_bix,
> it's impossible to tell if they would need an adjustment
> or not if their values were higher. */
> }
> + if (test_bit(ACPI_BATTERY_QUIRK_DEGRADED_FULL_CHARGE, &battery->flags) &&
> + battery->capacity_now > battery->full_charge_capacity)
> + battery->capacity_now = battery->full_charge_capacity;
> +
> return result;
> }
>
> @@ -567,6 +581,10 @@ static int acpi_battery_get_state(struct acpi_battery *battery)
> battery->capacity_now = battery->capacity_now *
> 10000 / battery->design_voltage;
> }
> + if (test_bit(ACPI_BATTERY_QUIRK_DEGRADED_FULL_CHARGE, &battery->flags) &&
> + battery->capacity_now > battery->full_charge_capacity)
> + battery->capacity_now = battery->full_charge_capacity;
> +
> return result;
> }
>
> @@ -743,6 +761,15 @@ static void acpi_battery_quirks(struct acpi_battery *battery)
> }
> }
> }
> +
> + if (test_bit(ACPI_BATTERY_QUIRK_DEGRADED_FULL_CHARGE, &battery->flags))
> + return;
> +
> + if (acpi_battery_is_degraded(battery) &&
> + battery->capacity_now > battery->full_charge_capacity) {
> + set_bit(ACPI_BATTERY_QUIRK_DEGRADED_FULL_CHARGE, &battery->flags);
> + battery->capacity_now = battery->full_charge_capacity;
> + }
> }
>
> static int acpi_battery_update(struct acpi_battery *battery, bool resume)
> --
> 2.7.4
>
Just a friendly reminder.
Laszlo
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