2021-09-14 12:21:06

by Sebastian Krzyszkowiak

Subject: [PATCH v2 2/2] power: supply: max17042_battery: Prevent int underflow in set_soc_threshold

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: <[email protected]>
Signed-off-by: Sebastian Krzyszkowiak <[email protected]>
---
v2: added commit description
---
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 da78ffe6a3ec..189c1979bc7b 100644
--- a/drivers/power/supply/max17042_battery.c
+++ b/drivers/power/supply/max17042_battery.c
@@ -857,7 +857,8 @@ 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);
}

--
2.33.0

2021-09-16 10:28:34

by Krzysztof Kozlowski

Subject: Re: [PATCH v2 2/2] power: supply: max17042_battery: Prevent int underflow in set_soc_threshold

On 14/09/2021 14:18, Sebastian Krzyszkowiak wrote:
> 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: <[email protected]>
> Signed-off-by: Sebastian Krzyszkowiak <[email protected]>
> ---
> v2: added commit description
> ---


Reviewed-by: Krzysztof Kozlowski <[email protected]>


Best regards,
Krzysztof