diff options
| author | Peter Marheine <pmarheine@chromium.org> | 2025-05-08 12:41:45 +1000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-06-27 11:11:28 +0100 |
| commit | e8cd4a8d5b885693fa2ab0dfbf550c2a2e43b53d (patch) | |
| tree | 75615a7517bb7de801202f436d63e1ffd62786e1 | |
| parent | 05713a9fc20a0ec3e62798448c048cc3c8e66c20 (diff) | |
ACPI: battery: negate current when discharging
[ 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>
| -rw-r--r-- | drivers/acpi/battery.c | 19 |
1 files changed, 16 insertions, 3 deletions
diff --git a/drivers/acpi/battery.c b/drivers/acpi/battery.c index 65fa3444367a1..6a7ac34d73bda 100644 --- a/drivers/acpi/battery.c +++ b/drivers/acpi/battery.c @@ -243,10 +243,23 @@ 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: |