On Wed, Feb 05, 2025 at 06:22:18AM +0100, Dimitri Fedrau wrote:
> Am Tue, Feb 04, 2025 at 05:54:53PM +0000 schrieb Russell King (Oracle):
> > On Tue, Feb 04, 2025 at 02:09:16PM +0100, Dimitri Fedrau via B4 Relay wrote:
> > > #if IS_ENABLED(CONFIG_OF_MDIO)
> > > -static int phy_get_int_delay_property(struct device *dev, const char *name)
> > > +static int phy_get_u32_property(struct device *dev, const char *name)
> > > {
> > > s32 int_delay;
> > > int ret;
> > > @@ -3108,7 +3108,7 @@ static int phy_get_int_delay_property(struct device *dev, const char *name)
> > > return int_delay;
> >
> > Hmm. You're changing the name of this function from "int" to "u32", yet
> > it still returns "int".
> >
>
> I just wanted to reuse code for retrieving the u32, I found
> phy_get_int_delay_property and renamed it. But the renaming from "int"
> to "u32" is wrong as you outlined.
>
> > What range of values are you expecting to be returned by this function?
> > If it's the full range of u32 values, then that overlaps with the error
> > range returned by device_property_read_u32().
> >
>
> Values are in percent, u8 would already be enough, so it wouldn't
> overlap with the error range.
>
> > I'm wondering whether it would be better to follow the example set by
> > these device_* functions, and pass a pointer for the value to them, and
> > just have the return value indicating success/failure.
> >
>
> I would prefer this, but this would mean changes in phy_get_internal_delay
> if we don't want to duplicate code, as phy_get_internal_delay relies on
> phy_get_int_delay_property and we change function parameters of
> phy_get_int_delay_property as you described. I would switch from
> static int phy_get_int_delay_property(struct device *dev, const char *name)
> to
> static int phy_get_u32_property(struct device *dev, const char *name, u32 *val)
>
> Do you agree ?
This looks O.K. You should also rename the local variable int_delay.
Humm, that function has other issues.
static int phy_get_int_delay_property(struct device *dev, const char *name)
{
s32 int_delay;
int ret;
ret = device_property_read_u32(dev, name, &int_delay);
if (ret)
return ret;
return int_delay;
}
int_delay should really be a u32. if ret is not an error, there should
be a range check to ensure int_long actually fits in an s32, otherwise
-EINVAL, or maybe -ERANGE.
For delays, we never expect too much more than 2000ps, so no valid DT
blob should trigger issues here.
Andrew
