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

From: Guenter Roeck
Date: Wed Nov 18 2015 - 10:11:09 EST

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.


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