| Message ID | 20221028224052.293693-1-megi@xff.cz (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | power: supply: ip5xxx: Fix integer overflow in current_now calculation | expand |
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:
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@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. Thanks, I queued it with that change included. -- Sebastian > > > return 0; > > > > case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT: >
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:
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> --- drivers/power/supply/ip5xxx_power.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)