linux-stable/drivers/power
Mario Limonciello 2d9144c0ca power: supply: Fix logic checking if system is running from battery
[ Upstream commit 95339f40a8 ]

The logic used for power_supply_is_system_supplied() counts all power
supplies and assumes that the system is running from AC if there is
either a non-battery power-supply reporting to be online or if no
power-supplies exist at all.

The second rule is for desktop systems, that don't have any
battery/charger devices. These systems will incorrectly report to be
powered from battery once a device scope power-supply is registered
(e.g. a HID device), since these power-supplies increase the counter.

Apart from HID devices, recent dGPUs provide UCSI power supplies on a
desktop systems. The dGPU by default doesn't have anything plugged in so
it's 'offline'. This makes power_supply_is_system_supplied() return 0
with a count of 1 meaning all drivers that use this get a wrong judgement.

To fix this case adjust the logic to also examine the scope of the power
supply. If the power supply is deemed a device power supply, then don't
count it.

Cc: Evan Quan <Evan.Quan@amd.com>
Suggested-by: Lijo Lazar <Lijo.Lazar@amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-06-21 16:00:52 +02:00
..
reset power: reset: qcom-pon: add support for qcom,pmk8350-pon compatible string 2022-09-11 12:09:10 +02:00
supply power: supply: Fix logic checking if system is running from battery 2023-06-21 16:00:52 +02:00
Kconfig
Makefile