Re: [PATCH 0/2] Add provision to keep idle state disabled

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Many thanks again,

On 6/16/2023 4:25 PM, Ulf Hansson wrote:
On Wed, 14 Jun 2023 at 08:43, Tushar Nimkar <quic_tnimkar@xxxxxxxxxxx> wrote:


Right. I am not saying it's the perfect solution, but it seems like it
could potentially solve the problem for many cases.

If you want some help to turn the cpuidle-psci driver into a loadable
module, just reach out, I am happy to help.

Thanks :)
Making cpuidle-psci as loadable does not hold good for target does not support DLKM, in addition to it rpmh driver has dependency on cpuidle-psci for pm-domain and rpmh probe will get defer, their are driver which depends on rpmh probe like interconnect, clk etc. And eventually dependent driver probe defers which are essential for Linux boot-up. Hope you got scenario for getting probe defer if we make cpuidle-psci as loadable.

I have below options as well
[A]: Can we think of making "governor/param_governor" module_param_string, string named governor only to load. In that way need to remove check [3]. Let's say string passed as "teo" then it will not load "menu" and loads "teo" once comes-up.

[B]: Can we think of making cpuidle.off as writable, let governors to register (i.e remove check [4]) and allow cpuidle_init() to happen (i.e remove check [5]) So in this way cpuidle.off=1, your idle state can not be selected because [6] and later we can write off=0 to let same check [6] to fail.

[C]: Coming to this series approach...What is best way to utilize already present Flag-CPUIDLE_FLAG_OFF ? Since we can not add new DT property to take decision in driver as it's not HW feature to be expose in device tree [7]. Can we introduce new module_param() for making idle-state disable default and utilize CPUIDLE_FLAG_OFF? maybe similar to [8]

happy to hear your thoughts!


[3] https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/tree/drivers/cpuidle/governor.c?h=next-20230620#n93

[4] https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/tree/drivers/cpuidle/governor.c?h=next-20230620#n86

[5] https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/tree/drivers/cpuidle/cpuidle.c?h=next-20230620#n808

[6] https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/tree/kernel/sched/idle.c?h=next-20230620#n167

[7] https://lore.kernel.org/lkml/20230608085544.16211-1-quic_tnimkar@xxxxxxxxxxx/T/#m5d6012b0dfcff700f48c0efbba629382f18ee33b

[8] https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/tree/drivers/idle/intel_idle.c?h=next-20230620#n2160
[...]

Kind regards
Uffe


Thanks,
Tushar



[Index of Archives]     [Linux ARM Kernel]     [Linux ARM]     [Linux Omap]     [Fedora ARM]     [Linux for Sparc]     [IETF Annouce]     [Security]     [Bugtraq]     [Linux MIPS]     [ECOS]     [Asterisk Internet PBX]     [Linux API]

  Powered by Linux