On 18/01/2019 16:23, Catalin Marinas wrote:

On Tue, Jan 08, 2019 at 02:07:27PM +0000, Julien Thierry wrote:

quoted

CPU does not received signals for interrupts with a priority masked by
ICC_PMR_EL1. This means the CPU might not come back from a WFI
instruction.

Make sure ICC_PMR_EL1 does not mask interrupts when doing a WFI.

Since the logic of cpu_do_idle is becoming a bit more complex than just
two instructions, lets turn it from ASM to C.

I haven't checked all the call paths, so asking here: does the core code
normally call arch_cpu_idle() with IRQs off?

If you look at do_idle() in kernel/sched/idle.c, it does:

	while (!need_resched()) {
		[...]
		local_irq_disable();
		arch_cpu_idle_enter();

		[...]
		} else {
			cpuidle_idle_call();
		}
	}


Then cpuidle_idle_call() will call default_idle_call() (which calls
arch_cpu_idle()) either directly or via the cpuidle driver. My
understanding is that it always does the call with interrupts disabled.

Thanks,

-- 
Julien Thierry

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