[PATCH V2 01/14] clk: add helper functions clk_prepare_enable and clk_disable_unprepare
Sascha Hauer
s.hauer at pengutronix.de
Fri Nov 11 03:49:50 EST 2011
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.
Sascha
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