[PATCH] power: supply: ip5xxx: Fix integer overflow in current_now calculation

From: Ondrej Jirman
Date: Fri Oct 28 2022 - 18:41:22 EST


When current is larger than ~2A, the multiplication in current_now
property overflows and the kernel reports invalid negative current
value. Change the numerator and denominator while preserving their
ratio to allow up to +-6A before the overflow.

Fixes: 75853406fa27 ("power: supply: Add a driver for Injoinic power bank ICs")
Signed-off-by: Ondrej Jirman <megi@xxxxxx>
---
drivers/power/supply/ip5xxx_power.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/power/supply/ip5xxx_power.c b/drivers/power/supply/ip5xxx_power.c
index 02ee4d252a3e..f39cb2f7aa11 100644
--- a/drivers/power/supply/ip5xxx_power.c
+++ b/drivers/power/supply/ip5xxx_power.c
@@ -398,7 +398,7 @@ static int ip5xxx_battery_get_property(struct power_supply *psy,
ret = ip5xxx_battery_read_adc(ip5xxx, IP5XXX_BATIADC_DAT0,
IP5XXX_BATIADC_DAT1, &raw);

- val->intval = DIV_ROUND_CLOSEST(raw * 745985, 1000);
+ val->intval = DIV_ROUND_CLOSEST(raw * 261095, 350);
return 0;

case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT:
--
2.38.1