Nokia N900: Proper C-states

2016-01-02 Thread Pali Rohár 
Hello,

due to this Daniel Lezcano commit (ARM: OMAP3: cpuidle - remove rx51
cpuidle parameters table)

https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=231900afba52d6faddfb480cde4132d4edc089bc

we need patch cpuidle34xx.c code to fix commit for Nokia N900. See:

https://github.com/pali/linux-n900/commit/e147fd4b678f1f3d7a5235287910960bd41e04dc

As Nokia N900 code is converting from legacy board code to DST, I would
like to know how to patch correctly omap3_idle_driver in DTS with
correct values measured for Nokia N900. Thanks!

-- 
Pali Rohár
pali.ro...@gmail.com


signature.asc
Description: This is a digitally signed message part.

Re: Nokia N900: Proper C-states

2016-01-02 Thread Daniel Lezcano 

On 01/02/2016 03:26 PM, Pali Rohár wrote:

Hello,

due to this Daniel Lezcano commit (ARM: OMAP3: cpuidle - remove rx51
cpuidle parameters table)

https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=231900afba52d6faddfb480cde4132d4edc089bc

we need patch cpuidle34xx.c code to fix commit for Nokia N900. See:

https://github.com/pali/linux-n900/commit/e147fd4b678f1f3d7a5235287910960bd41e04dc

As Nokia N900 code is converting from legacy board code to DST, I would
like to know how to patch correctly omap3_idle_driver in DTS with
correct values measured for Nokia N900. Thanks!


Hi Pali,

the conversion to the DT based arm cpuidle driver could be a bit complex 
with one issue (index 0 != cpu_do_idle()) and one performance regression 
(cpu_pm_enter/exit will be called in retention mode, even if this is not 
needed).


It will result in a PM code only on one side and on the other side, the 
generic cpuidle-arm.c driver will be used instead with the DT 
definition. It is worth to the conversion because the result will be 
nice IMO.


Added Lorenzo who is initially author of the arm generic driver. We 
already discussed in the past about those two issues above and I think 
this is something we should improve.




--
  Linaro.org │ Open source software for ARM SoCs

Follow Linaro:   Facebook |
 Twitter |
 Blog

--
To unsubscribe from this list: send the line "unsubscribe linux-omap" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html