[PATCH V2 01/14] clk: add helper functions clk_prepare_enable and clk_disable_unprepare

[Richard Zhao]

On Fri, Nov 11, 2011 at 09:49:50AM +0100, Sascha Hauer wrote:
> On Fri, Nov 11, 2011 at 09:10:16AM +0800, Richard Zhao wrote:
> > Signed-off-by: Richard Zhao <richard.zhao at linaro.org>
> > ---
> >  include/linux/clk.h |   19 +++++++++++++++++++
> >  1 files changed, 19 insertions(+), 0 deletions(-)
> > 
> > diff --git a/include/linux/clk.h b/include/linux/clk.h
> > index 7213b52..63985f7 100644
> > --- a/include/linux/clk.h
> > +++ b/include/linux/clk.h
> > @@ -107,6 +107,25 @@ static inline void clk_unprepare(struct clk *clk)
> >  }
> >  #endif
> >  
> > +static inline int clk_prepare_enable(struct clk *clk)
> > +{
> > +	int ret;
> > +
> > +	ret = clk_prepare(clk);
> > +	if (!ret)
> > +		ret = clk_enable(clk);
> > +	if (ret)
> > +		clk_unprepare(clk);
> 
> As Baruch already pointed out this is hard to read. Also it contains a
> bug. When clk_prepare fails clk_unprepare is called afterwards.
> 
> Hint: Kernel guys are not afraid of having multiple return statements
> in a function, instead they like it when something is handled early
> without having to read the rest of the function.
{
	int ret;

	ret = clk_prepare(clk);
	if (ret)
		return ret;
	ret = clk_enable(clk);
	if (ret)
		clk_unprepare(clk);
	return ret;

Like above code? Thanks for review.

Richard
> 
> Sascha
> 
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