This is a note to let you know that I've just added the patch titled
power: supply: Fix logic checking if system is running from battery
to the 4.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
power-supply-fix-logic-checking-if-system-is-running.patch
and it can be found in the queue-4.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit af08483d64ee56eb5262373cf5f95d8c6a099e10
Author: Mario Limonciello <mario.limonciello@xxxxxxx>
Date: Tue May 16 13:25:40 2023 -0500
power: supply: Fix logic checking if system is running from battery
[ Upstream commit 95339f40a8b652b5b1773def31e63fc53c26378a ]
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@xxxxxxx>
Suggested-by: Lijo Lazar <Lijo.Lazar@xxxxxxx>
Signed-off-by: Mario Limonciello <mario.limonciello@xxxxxxx>
Signed-off-by: Sebastian Reichel <sebastian.reichel@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/power/supply/power_supply_core.c b/drivers/power/supply/power_supply_core.c
index 409ecff1a51a7..67766b500325f 100644
--- a/drivers/power/supply/power_supply_core.c
+++ b/drivers/power/supply/power_supply_core.c
@@ -349,6 +349,10 @@ static int __power_supply_is_system_supplied(struct device *dev, void *data)
struct power_supply *psy = dev_get_drvdata(dev);
unsigned int *count = data;
+ if (!psy->desc->get_property(psy, POWER_SUPPLY_PROP_SCOPE, &ret))
+ if (ret.intval == POWER_SUPPLY_SCOPE_DEVICE)
+ return 0;
+
(*count)++;
if (psy->desc->type != POWER_SUPPLY_TYPE_BATTERY)
if (!psy->desc->get_property(psy, POWER_SUPPLY_PROP_ONLINE,
@@ -367,8 +371,8 @@ int power_supply_is_system_supplied(void)
__power_supply_is_system_supplied);
/*
- * If no power class device was found at all, most probably we are
- * running on a desktop system, so assume we are on mains power.
+ * If no system scope power class device was found at all, most probably we
+ * are running on a desktop system, so assume we are on mains power.
*/
if (count == 0)
return 1;
