linux-kernel - Re: [PATCH v2 1/6] idle: move the cpuidle entry point to the generic idle loop

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Message-ID: <20140130180659.GI5002@laptop.programming.kicks-ass.net>
Date:	Thu, 30 Jan 2014 19:06:59 +0100
From:	Peter Zijlstra <peterz@...radead.org>
To:	Daniel Lezcano <daniel.lezcano@...aro.org>
Cc:	Nicolas Pitre <nicolas.pitre@...aro.org>,
	Preeti U Murthy <preeti@...ux.vnet.ibm.com>,
	Olof Johansson <olof@...om.net>,
	Russell King <linux@....linux.org.uk>,
	Benjamin Herrenschmidt <benh@...nel.crashing.org>,
	Paul Mundt <lethal@...ux-sh.org>,
	Thomas Gleixner <tglx@...utronix.de>,
	Ingo Molnar <mingo@...hat.com>,
	"Rafael J. Wysocki" <rjw@...ysocki.net>,
	linaro-kernel@...ts.linaro.org, linux-pm@...r.kernel.org,
	linux-sh@...r.kernel.org, linux-kernel@...r.kernel.org,
	linuxppc-dev@...ts.ozlabs.org, linux-arm-kernel@...ts.infradead.org
Subject: Re: [PATCH v2 1/6] idle: move the cpuidle entry point to the generic
 idle loop

On Thu, Jan 30, 2014 at 06:28:52PM +0100, Daniel Lezcano wrote:
> Ok, I think the mess is coming from 'default_idle' which does not re-enable
> the local_irq but used from different places like amd_e400_idle and
> apm_cpu_idle.
> 
> void default_idle(void)
> {
>         trace_cpu_idle_rcuidle(1, smp_processor_id());
>         safe_halt();
>         trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, smp_processor_id());
> }
> 
> Considering the system configured without cpuidle because this one *always*
> enable the local irq, we have the different cases:
> 
> x86_idle = default_idle();
> ==> local_irq_enable is missing
> 

safe_halt() is "sti; hlt" and so very much does the irq_enable.
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