Re: [PATCH v2 08/44] cpuidle,imx6: Push RCU-idle into driver

Frederic Weisbecker
2022-09-19T14:21:33Z

On Mon, Sep 19, 2022 at 11:59:47AM +0200, Peter Zijlstra wrote:
> Doing RCU-idle outside the driver, only to then temporarily enable it
> again, at least twice, before going idle is daft.

Hmm, what ends up calling RCU_IDLE() here? Also what about
cpu_do_idle()?

Thanks.

>
> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
> ---
> arch/arm/mach-imx/cpuidle-imx6sx.c | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> --- a/arch/arm/mach-imx/cpuidle-imx6sx.c
> +++ b/arch/arm/mach-imx/cpuidle-imx6sx.c
> @@ -47,7 +47,9 @@ static int imx6sx_enter_wait(struct cpui
> cpu_pm_enter();
> cpu_cluster_pm_enter();
>
> + ct_idle_enter();
> cpu_suspend(0, imx6sx_idle_finish);
> + ct_idle_exit();
>
> cpu_cluster_pm_exit();
> cpu_pm_exit();
> @@ -87,7 +89,8 @@ static struct cpuidle_driver imx6sx_cpui
> */
> .exit_latency = 300,
> .target_residency = 500,
> - .flags = CPUIDLE_FLAG_TIMER_STOP,
> + .flags = CPUIDLE_FLAG_TIMER_STOP |
> + CPUIDLE_FLAG_RCU_IDLE,
> .enter = imx6sx_enter_wait,
> .name = "LOW-POWER-IDLE",
> .desc = "ARM power off",
>
>