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

[Rafael J. Wysocki]

On Thursday, June 04, 2015 12:06:36 PM Viresh Kumar wrote:
> 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>

Queued up for 4.2, thanks!


-- 
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.