linux-kernel - Re: [PATCH 195/228] cpufreq: kirkwood: remove calls to cpufreq_notify

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Date:	Fri, 13 Sep 2013 21:53:58 +0530
From:	Viresh Kumar <viresh.kumar@...aro.org>
To:	Andrew Lunn <andrew@...n.ch>
Cc:	"Rafael J. Wysocki" <rjw@...k.pl>,
	Lists linaro-kernel <linaro-kernel@...ts.linaro.org>,
	Patch Tracking <patches@...aro.org>,
	"cpufreq@...r.kernel.org" <cpufreq@...r.kernel.org>,
	"linux-pm@...r.kernel.org" <linux-pm@...r.kernel.org>,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
	"linux-arm-kernel@...ts.infradead.org" 
	<linux-arm-kernel@...ts.infradead.org>
Subject: Re: [PATCH 195/228] cpufreq: kirkwood: remove calls to cpufreq_notify_transition()

On 13 September 2013 21:48, Andrew Lunn <andrew@...n.ch> wrote:
> On Fri, Sep 13, 2013 at 06:32:21PM +0530, Viresh Kumar wrote:
>
>> -     if (freqs.old != freqs.new) {
>> -             local_irq_disable();
>> -
>> -             /* Disable interrupts to the CPU */
>> -             reg = readl_relaxed(priv.base);
>> -             reg |= CPU_SW_INT_BLK;
>> -             writel_relaxed(reg, priv.base);
>> -
>> -             switch (state) {
>> -             case STATE_CPU_FREQ:
>> -                     clk_disable(priv.powersave_clk);
>> -                     break;
>> -             case STATE_DDR_FREQ:
>> -                     clk_enable(priv.powersave_clk);
>> -                     break;
>> -             }
>
> Hi Viresh
>
> I see you removed the test that the old and the new frequency are
> different. Is this guaranteed by the core? Because if not, you can
> lockup the CPU. The call to cpu_do_idle() will never return.

Yes, that's guaranteed by core: patch 181..
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