Message-ID: <52E02DCC.1000404@wwwdotorg.org>
Date: Wed, 22 Jan 2014 13:45:00 -0700
From: Stephen Warren <swarren@wwwdotorg.org>
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To: Alexandre Courbot <acourbot@nvidia.com>,
        Thierry Reding <thierry.reding@gmail.com>,
        Russell King <linux@arm.linux.org.uk>
CC: Olof Johansson <olof@lixom.net>, linux-arm-kernel@lists.infradead.org,
        linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org,
        gnurou@gmail.com
Subject: Re: [PATCH 5/5] ARM: tegra: cpuidle: use firmware call for power
 down
References: <1390299016-14105-1-git-send-email-acourbot@nvidia.com> <1390299016-14105-6-git-send-email-acourbot@nvidia.com>
In-Reply-To: <1390299016-14105-6-git-send-email-acourbot@nvidia.com>
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On 01/21/2014 03:10 AM, Alexandre Courbot wrote:
> Invoke the do_idle() firmware call before suspending a CPU so that the
> underlying firmware (if any) can take necessary action.

> diff --git a/arch/arm/mach-tegra/cpuidle-tegra114.c b/arch/arm/mach-tegra/cpuidle-tegra114.c

> @@ -45,6 +46,8 @@ static int tegra114_idle_power_down(struct cpuidle_device *dev,
>  
>  	clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER, &dev->cpu);
>  
> +	call_firmware_op(do_idle);
> +
>  	cpu_suspend(0, tegra30_sleep_cpu_secondary_finish);
>  
>  	clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_EXIT, &dev->cpu);

Don't you need to have the kernel also *not* do something when entering
idle; doesn't the FW op replace some of the register writes that the
kernel would otherwise be doing?
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