From 95339f40a8b652b5b1773def31e63fc53c26378a Mon Sep 17 00:00:00 2001
From: Mario Limonciello <mario.limonciello@amd.com>
Date: Tue, 16 May 2023 13:25:40 -0500
Subject: [PATCH] power: supply: Fix logic checking if system is running from battery
Git-commit: 95339f40a8b652b5b1773def31e63fc53c26378a
Patch-mainline: v6.4-rc4
References: git-fixes
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>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
drivers/power/supply/power_supply_core.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/drivers/power/supply/power_supply_core.c b/drivers/power/supply/power_supply_core.c
index d1b19027f53b..3791aec69ddc 100644
--- a/drivers/power/supply/power_supply_core.c
+++ b/drivers/power/supply/power_supply_core.c
@@ -348,6 +348,10 @@ 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,
@@ -366,8 +370,8 @@ 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;
--
2.35.3