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SubjectRe: [PATCH] power: supply: ip5xxx: Fix integer overflow in current_now calculation
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On 10/28/22 17:40, Ondrej Jirman wrote:
> 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@xff.cz>

Reviewed-by: Samuel Holland <samuel@sholland.org>

> ---
> 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);

DIV_ROUND_CLOSEST(raw * 149197, 200) would be marginally more accurate,
but it doesn't matter in practice.

> return 0;
>
> case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT:

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