Re: [PATCH] mmc: sh_mmcif: simplify clock divisor calculation

[Chris Ball <cjb@laptop.org>]

Hi,

On Wed, Nov 23 2011, Guennadi Liakhovetski wrote:
> Replace ilog2(__rounddown_pow_of_two(x)) with the equivalent but much
> simpler fls(x) - 1.
>
> Reported-by: Andrew Morton <akpm@linux-foundation.org>
> Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
> ---
>  drivers/mmc/host/sh_mmcif.c |    3 ++-
>  1 files changed, 2 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/mmc/host/sh_mmcif.c b/drivers/mmc/host/sh_mmcif.c
> index c021482..824fee5 100644
> --- a/drivers/mmc/host/sh_mmcif.c
> +++ b/drivers/mmc/host/sh_mmcif.c
> @@ -16,6 +16,7 @@
>   *
>   */
>  
> +#include <linux/bitops.h>
>  #include <linux/clk.h>
>  #include <linux/completion.h>
>  #include <linux/delay.h>
> @@ -386,7 +387,7 @@ static void sh_mmcif_clock_control(struct sh_mmcif_host *host, unsigned int clk)
>  		sh_mmcif_bitset(host, MMCIF_CE_CLK_CTRL, CLK_SUP_PCLK);
>  	else
>  		sh_mmcif_bitset(host, MMCIF_CE_CLK_CTRL, CLK_CLEAR &
> -			(ilog2(__rounddown_pow_of_two(host->clk / clk)) << 16));
> +				((fls(host->clk / clk) - 1) << 16));
>  
>  	sh_mmcif_bitset(host, MMCIF_CE_CLK_CTRL, CLK_ENABLE);
>  }

Thanks, pushed to mmc-next for 3.3.

- Chris.
-- 
Chris Ball   <cjb@laptop.org>   <http://printf.net/>
One Laptop Per Child