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

[Sebastian Reichel]

Hi,

On Fri, Oct 28, 2022 at 06:06:07PM -0500, Samuel Holland wrote:
> 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@xxxxxx>
> 
> Reviewed-by: Samuel Holland <samuel@xxxxxxxxxxxx>
> 
> > ---
> >  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.

Thanks, I queued it with that change included.

-- Sebastian

> 
> >  		return 0;
> >  
> >  	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT:
>

Attachment: signature.asc
Description: PGP signature