From: Hans de Goede <hdegoede@xxxxxxxxxx> commit cc99f0ad52467028cb1251160f23ad4bb65baf20 upstream. Commit b41901a2cf06 ("ACPI / battery: Do not export energy_full[_design] on devices without full_charge_capacity") added support for some (broken) devices which always report 0 for both design- and full_charge-capacity. This assumes that if the capacity is not being reported it is 0. The ThunderSoft TS178 tablet's _BIX implementation falsifies this assumption. It reports ACPI_BATTERY_VALUE_UNKNOWN (-1) as full_charge_capacity, which we treat as a valid value which causes several problems. This commit fixes this by adding a new ACPI_BATTERY_CAPACITY_VALID() helper which checks that the value is not 0 and not -1; and using this whenever we need to test if either design_capacity or full_charge_capacity is valid. Fixes: b41901a2cf06 ("ACPI / battery: Do not export energy_full[_design] on devices without full_charge_capacity") Cc: 4.19+ <stable@xxxxxxxxxxxxxxx> # 4.19+ Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/acpi/battery.c | 19 ++++++++++++------- 1 file changed, 12 insertions(+), 7 deletions(-) --- a/drivers/acpi/battery.c +++ b/drivers/acpi/battery.c @@ -51,6 +51,8 @@ #define PREFIX "ACPI: " #define ACPI_BATTERY_VALUE_UNKNOWN 0xFFFFFFFF +#define ACPI_BATTERY_CAPACITY_VALID(capacity) \ + ((capacity) != 0 && (capacity) != ACPI_BATTERY_VALUE_UNKNOWN) #define ACPI_BATTERY_DEVICE_NAME "Battery" @@ -205,7 +207,8 @@ static int acpi_battery_is_charged(struc static bool acpi_battery_is_degraded(struct acpi_battery *battery) { - return battery->full_charge_capacity && battery->design_capacity && + return ACPI_BATTERY_CAPACITY_VALID(battery->full_charge_capacity) && + ACPI_BATTERY_CAPACITY_VALID(battery->design_capacity) && battery->full_charge_capacity < battery->design_capacity; } @@ -276,14 +279,14 @@ static int acpi_battery_get_property(str break; case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN: case POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN: - if (battery->design_capacity == ACPI_BATTERY_VALUE_UNKNOWN) + if (!ACPI_BATTERY_CAPACITY_VALID(battery->design_capacity)) ret = -ENODEV; else val->intval = battery->design_capacity * 1000; break; case POWER_SUPPLY_PROP_CHARGE_FULL: case POWER_SUPPLY_PROP_ENERGY_FULL: - if (battery->full_charge_capacity == ACPI_BATTERY_VALUE_UNKNOWN) + if (!ACPI_BATTERY_CAPACITY_VALID(battery->full_charge_capacity)) ret = -ENODEV; else val->intval = battery->full_charge_capacity * 1000; @@ -296,11 +299,12 @@ static int acpi_battery_get_property(str val->intval = battery->capacity_now * 1000; break; case POWER_SUPPLY_PROP_CAPACITY: - if (battery->capacity_now && battery->full_charge_capacity) + if (battery->capacity_now == ACPI_BATTERY_VALUE_UNKNOWN || + !ACPI_BATTERY_CAPACITY_VALID(battery->full_charge_capacity)) + ret = -ENODEV; + else val->intval = battery->capacity_now * 100/ battery->full_charge_capacity; - else - val->intval = 0; break; case POWER_SUPPLY_PROP_CAPACITY_LEVEL: if (battery->state & ACPI_BATTERY_STATE_CRITICAL) @@ -812,7 +816,8 @@ static int sysfs_add_battery(struct acpi battery->bat_desc.properties = charge_battery_props; battery->bat_desc.num_properties = ARRAY_SIZE(charge_battery_props); - } else if (battery->full_charge_capacity == 0) { + } else if (!ACPI_BATTERY_CAPACITY_VALID( + battery->full_charge_capacity)) { battery->bat_desc.properties = energy_battery_full_cap_broken_props; battery->bat_desc.num_properties =