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From:   Arnd Bergmann <arnd@arndb.de>
Date:   Wed, 8 Jun 2022 18:28:33 +0200
Message-ID: <CAK8P3a0g-fNu9=BUECSXcNeWT7XWHQMnSXZE-XYE+5eakHxKxA@mail.gmail.com>
Subject: Re: [PATCH 33/36] cpuidle,omap3: Use WFI for omap3_pm_idle()
To:     Peter Zijlstra <peterz@infradead.org>
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On Wed, Jun 8, 2022 at 4:27 PM Peter Zijlstra <peterz@infradead.org> wrote:
>
> arch_cpu_idle() is a very simple idle interface and exposes only a
> single idle state and is expected to not require RCU and not do any
> tracing/instrumentation.
>
> As such, omap_sram_idle() is not a valid implementation. Replace it
> with the simple (shallow) omap3_do_wfi() call. Leaving the more
> complicated idle states for the cpuidle driver.
>
> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>

I see similar code in omap2:

omap2_pm_idle()
 -> omap2_enter_full_retention()
     -> omap2_sram_suspend()

Is that code path safe to use without RCU or does it need a similar change?

        Arnd