From mboxrd@z Thu Jan  1 00:00:00 1970
From: Frederic Weisbecker <frederic@kernel.org>
Subject: Re: [PATCH v2 10/44] cpuidle,armada: Push RCU-idle into driver
Date: Mon, 19 Sep 2022 16:39:07 +0200
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 <20220919101521.004425686@infradead.org>
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To: Peter Zijlstra <peterz@infradead.org>
Cc: richard.henderson@linaro.org, ink@jurassic.park.msu.ru, mattst88@gmail.com, vgupta@kernel.org, linux@armlinux.org.uk, ulli.kroll@googlemail.com, linus.walleij@linaro.org, shawnguo@kernel.org, Sascha Hauer <s.hauer@pengutronix.de>, kernel@pengutronix.de, festevam@gmail.com, linux-imx@nxp.com, tony@atomide.com, khilman@kernel.org, catalin.marinas@arm.com, will@kernel.org, guoren@kernel.org, bcain@quicinc.com, chenhuacai@kernel.org, kernel@xen0n.name, geert@linux-m68k.org, sammy@sammy.net, monstr@monstr.eu, tsbogend@alpha.franken.de, dinguyen@kernel.org, jonas@southpole.se, stefan.kristiansson@saunalahti.fi, shorne@gmail.com, James.Bottomley@HansenPartnership.com, deller@gmx.de, mpe@ellerman.id.au, npiggin@gmail.com, christophe.leroy@csgroup.eu, paul.walmsley@sifive.com, palmer@dabbel

On Mon, Sep 19, 2022 at 11:59:49AM +0200, Peter Zijlstra wrote:
> Doing RCU-idle outside the driver, only to then temporarily enable it
> again before going idle is daft.

Ah wait, now I see, that's cpu_pm_enter()/cpu_pm_exit() -> cpu_pm_notify*() the culprits.
Might be worth adding a short note about that on your changelogs.

> 
> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
> ---
>  drivers/cpuidle/cpuidle-mvebu-v7.c |    7 +++++++
>  1 file changed, 7 insertions(+)
> 
> --- a/drivers/cpuidle/cpuidle-mvebu-v7.c
> +++ b/drivers/cpuidle/cpuidle-mvebu-v7.c
> @@ -36,7 +36,10 @@ static int mvebu_v7_enter_idle(struct cp
>  	if (drv->states[index].flags & MVEBU_V7_FLAG_DEEP_IDLE)
>  		deepidle = true;
>  
> +	ct_idle_enter();
>  	ret = mvebu_v7_cpu_suspend(deepidle);
> +	ct_idle_exit();

And then yes of course:

Reviewed-by: Frederic Weisbecker <frederic@kernel.org>