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Re: [PATCH 33/36] cpuidle,omap3: Use WFI for omap3_pm_idle()
 
- To: Arnd Bergmann <arnd@xxxxxxxx>
 
- From: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
 
- Date: Thu, 9 Jun 2022 11:40:46 +0200
 
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- Delivery-date: Thu, 09 Jun 2022 10:47:23 +0000
 
- List-id: Xen developer discussion <xen-devel.lists.xenproject.org>
 
 
 
On Wed, Jun 08, 2022 at 06:28:33PM +0200, Arnd Bergmann wrote:
> On Wed, Jun 8, 2022 at 4:27 PM Peter Zijlstra <peterz@xxxxxxxxxxxxx> 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@xxxxxxxxxxxxx>
> 
> 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?
It needs a similar change, clearly I was running on fumes to not have
found that when grepping around the omap code :/
 
 
    
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