Re: [PATCH v3 2/5] mfd: syscon: add a DT property to set value width

[Guenter Roeck]

On 11/18/2015 12:21 AM, Lee Jones wrote:
[ ... ]
> > > Or, for more clarity:
> > >
> > >    of_property_read_u32(np, "bus-width", &bus_width);
> > >    if (bus_width)
> > >
> > > If you choose this version (which I think is my preferred method, don't
> > > forget to initialise 'bus_width' to zero.
> > Ignoring an error and depending on bus_width==0 to determine if the property
> > was provided seems odd, especially since it would "hide" if the bus-width
> > property is set to 0. In the original code, this would be detected as error.
>
> I'm not sure what you mean.  If bus_width==0, then a problem has
> occurred and we will not use the value.  If bus_width!=0 then we can
> assume that it's been set and (as the comment describes) the value
> will be checked for errors in regmap_init_mmio().

Your proposed code does not distinguish a missing property from "bus-width = <0>;".
It will silently ignore this case.

Guenter

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/