[PATCH 3/3] clk: divider: fix calculation of initial best divider when rounding to closest

Maxime Coquelin maxime.coquelin at st.com
Mon Feb 23 01:42:12 PST 2015


Hi Uwe,

On 02/21/2015 11:40 AM, Uwe Kleine-König wrote:
> Similar to the reasoning for the previous commit
>
> 	DIV_ROUND_CLOSEST(parent_rate, rate)
>
> might not be the best integer divisor to get a good approximation for
> rate from parent_rate (given the metric for CLK_DIVIDER_ROUND_CLOSEST).
>
> For example assume a parent rate of 1000 Hz and a target rate of 700.
> Using DIV_ROUND_CLOSEST the suggested divisor gets calculated to 1
> resulting in a target rate of 1000 with a delta of 300 to the desired
> rate. With choosing 2 as divisor however the resulting rate is 500 which
> is nearer to 700.
>
> Signed-off-by: Uwe Kleine-König <u.kleine-koenig at pengutronix.de>
> ---
>   drivers/clk/clk-divider.c | 13 +++++++------
>   1 file changed, 7 insertions(+), 6 deletions(-)
>

This is correct. Thanks for fixing this.

You can add my:
Acked-by: Maxime Coquelin <maxime.coquelin at st.com>


Best regards,
Maxime



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