[PATCH] cpufreq: qoriq: optimize the CPU frequency switching time

Viresh Kumar viresh.kumar at linaro.org
Thu Jun 4 16:36:36 AEST 2015


On 04-06-15, 14:25, Yuantian.Tang at freescale.com wrote:
> From: Tang Yuantian <Yuantian.Tang at freescale.com>
> 
> Each time the CPU switches its frequency, the clock nodes in
> DTS are walked through to find proper clock source. This is
> very time-consuming, for example, it is up to 500+ us on T4240.
> Besides, switching time varies from clock to clock.
> To optimize this, each input clock of CPU is buffered, so that
> it can be picked up instantly when needed.
> 
> Since for each CPU each input clock is stored in a pointer
> which takes 4 or 8 bytes memory and normally there are several
> input clocks per CPU, that will not take much memory as well.

Not sure how it got included in this form in the first place. :)

> Signed-off-by: Tang Yuantian <Yuantian.Tang at freescale.com>
> ---
>  drivers/cpufreq/qoriq-cpufreq.c | 32 +++++++++++++++++++++-----------
>  1 file changed, 21 insertions(+), 11 deletions(-)

Acked-by: Viresh Kumar <viresh.kumar at linaro.org>

-- 
viresh


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