From e660dbb68c6b3f7b9eb8b9775846a44f9798b719 Mon Sep 17 00:00:00 2001
From: Sebastian Krzyszkowiak <sebastian.krzyszkowiak@puri.sm>
Date: Tue, 14 Sep 2021 14:18:06 +0200
Subject: [PATCH] power: supply: max17042_battery: Prevent int underflow in set_soc_threshold
Git-commit: e660dbb68c6b3f7b9eb8b9775846a44f9798b719
Patch-mainline: v5.16-rc1
References: git-fixes stable-5.14.19
max17042_set_soc_threshold gets called with offset set to 1, which means
that minimum threshold value would underflow once SOC got down to 0,
causing invalid alerts from the gauge.
Fixes: e5f3872d2044 ("max17042: Add support for signalling change in SOC")
Cc: <stable@vger.kernel.org>
Signed-off-by: Sebastian Krzyszkowiak <sebastian.krzyszkowiak@puri.sm>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
drivers/power/supply/max17042_battery.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/power/supply/max17042_battery.c b/drivers/power/supply/max17042_battery.c
index 2eb61856f3e4..87128cf0d577 100644
--- a/drivers/power/supply/max17042_battery.c
+++ b/drivers/power/supply/max17042_battery.c
@@ -860,7 +860,8 @@ static void max17042_set_soc_threshold(struct max17042_chip *chip, u16 off)
regmap_read(map, MAX17042_RepSOC, &soc);
soc >>= 8;
soc_tr = (soc + off) << 8;
- soc_tr |= (soc - off);
+ if (off < soc)
+ soc_tr |= soc - off;
regmap_write(map, MAX17042_SALRT_Th, soc_tr);
}
--
2.26.2