Re: Nokia N900: Proper C-states

From: Daniel Lezcano
Date: Sat Jan 02 2016 - 17:01:02 EST


On 01/02/2016 03:26 PM, Pali RohÃr 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.



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