Re: [PATCH v2 4/4] backlight: pwm_bl: switch to power-of-2 base for fixed-point math

[Lee Jones]

On Tue, 08 Oct 2019, Rasmus Villemoes wrote:

> Using a power-of-2 instead of power-of-10 base makes the computations
> much cheaper. 2^16 is safe; retval never becomes more than 2^48 +
> 2^32/2. On a 32 bit platform, the very expensive 64/32 division at the
> end of cie1931() instead becomes essentially free (a shift by 32 is
> just a register rename).
> 
> Reviewed-by: Daniel Thompson <daniel.thompson@xxxxxxxxxx>
> Signed-off-by: Rasmus Villemoes <linux@xxxxxxxxxxxxxxxxxx>
> ---
>  drivers/video/backlight/pwm_bl.c | 22 ++++++++++++----------
>  1 file changed, 12 insertions(+), 10 deletions(-)

Applied, thanks.

-- 
Lee Jones [æçæ]
Linaro Services Technical Lead
Linaro.org â Open source software for ARM SoCs
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