5.10-stable review patch. If anyone has any objections, please let me know.
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From: Peter Marheine pmarheine@chromium.org
[ Upstream commit 234f71555019d308c6bc6f98c78c5551cb8cd56a ]
The ACPI specification requires that battery rate is always positive, but the kernel ABI for POWER_SUPPLY_PROP_CURRENT_NOW (Documentation/ABI/testing/sysfs-class-power) specifies that it should be negative when a battery is discharging. When reporting CURRENT_NOW, massage the value to match the documented ABI.
This only changes the sign of `current_now` and not `power_now` because documentation doesn't describe any particular meaning for `power_now` so leaving `power_now` unchanged is less likely to confuse userspace unnecessarily, whereas becoming consistent with the documented ABI is worth potentially confusing clients that read `current_now`.
Signed-off-by: Peter Marheine pmarheine@chromium.org Link: https://patch.msgid.link/20250508024146.1436129-1-pmarheine@chromium.org Signed-off-by: Rafael J. Wysocki rafael.j.wysocki@intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/acpi/battery.c | 19 ++++++++++++++++--- 1 file changed, 16 insertions(+), 3 deletions(-)
diff --git a/drivers/acpi/battery.c b/drivers/acpi/battery.c index f9fb092f33a26..4a188cc28b5ce 100644 --- a/drivers/acpi/battery.c +++ b/drivers/acpi/battery.c @@ -255,10 +255,23 @@ static int acpi_battery_get_property(struct power_supply *psy, break; case POWER_SUPPLY_PROP_CURRENT_NOW: case POWER_SUPPLY_PROP_POWER_NOW: - if (battery->rate_now == ACPI_BATTERY_VALUE_UNKNOWN) + if (battery->rate_now == ACPI_BATTERY_VALUE_UNKNOWN) { ret = -ENODEV; - else - val->intval = battery->rate_now * 1000; + break; + } + + val->intval = battery->rate_now * 1000; + /* + * When discharging, the current should be reported as a + * negative number as per the power supply class interface + * definition. + */ + if (psp == POWER_SUPPLY_PROP_CURRENT_NOW && + (battery->state & ACPI_BATTERY_STATE_DISCHARGING) && + acpi_battery_handle_discharging(battery) + == POWER_SUPPLY_STATUS_DISCHARGING) + val->intval = -val->intval; + break; case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN: case POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN: