On Fri, 18 May 2012, Paul Mundt wrote:
> On Thu, May 03, 2012 at 04:32:39PM +0100, Mark Brown wrote:
> > On Thu, May 03, 2012 at 05:05:34PM +0200, Guennadi Liakhovetski wrote:
> >
> > > - if (regulator == NULL || IS_ERR(regulator))
> > > + if (IS_ERR_OR_NULL(regulator))
> >
> > The bigger question here is why we're accepting NULL in the first place.
>
> I'm not sure about the regulator case, but it's been useful to support
> passing NULL around in the clock framework case. There are plenty of
> cases where a struct clk is optional and if we fail to find the clock we
> just set clk to NULL and continue on without having to constantly check
> the value of the clk pointer, which helps considerably when you consider
> the number of clk_enable/disable() pairs some drivers have.
>
> Presumably the same applies for regulators?
Right, but you normally do something like
priv->regulator = regulator_get();
...
regulator_put(priv->regulator);
Since regulator_get() only returns either a valid pointer or an ERR_PTR()
value, priv->regulator won't be NULL. Doing something like
priv->regulator = regulator_get();
if (IS_ERR(priv->regulator))
priv->regulator = NULL;
would seem too weird to me.
Thanks
Guennadi
---
Guennadi Liakhovetski, Ph.D.
Freelance Open-Source Software Developer
http://www.open-technology.de/
--
To unsubscribe from this list: send the line "unsubscribe linux-mmc" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
