From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lorenzo Pieralisi Subject: Re: [PATCH v3] ARM: tegra: cpuidle: implement cpuidle_state.enter_freeze() Date: Wed, 20 May 2015 09:44:41 +0100 Message-ID: <20150520084441.GA29274@red-moon> References: <1432046953-12945-1-git-send-email-tomeu.vizoso@collabora.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <1432046953-12945-1-git-send-email-tomeu.vizoso-ZGY8ohtN/8qB+jHODAdFcQ@public.gmane.org> Sender: linux-tegra-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Tomeu Vizoso Cc: "linux-pm-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "Rafael J. Wysocki" , Russell King , Stephen Warren , Thierry Reding , Alexandre Courbot , Kukjin Kim , Ingo Molnar , Bartlomiej Zolnierkiewicz , Daniel Lezcano , Thomas Gleixner , "linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org" , "linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" List-Id: linux-tegra@vger.kernel.org On Tue, May 19, 2015 at 03:49:12PM +0100, Tomeu Vizoso wrote: > This callback is expected to do the same as enter() but it has to > guarantee that interrupts aren't enabled at any point in its execution, > as the tick is frozen. > > It will be called when the system goes to suspend-to-idle and will > reduce power usage because CPUs won't be awaken for unnecessary IRQs. > > By setting the CPUIDLE_FLAG_TIMER_STOP flag, we can reuse the same code > for both the enter() and enter_freeze() callbacks. > > Signed-off-by: Tomeu Vizoso > Cc: Rafael J. Wysocki > > --- > > v3: * Set CPUIDLE_FLAG_TIMER_STOP to simplify things as suggested by > Lorenzo Pieralisi > v2: * Disable FIQs also when suspending-to-idle > --- > arch/arm/mach-tegra/cpuidle-tegra114.c | 13 +++++++++---- > 1 file changed, 9 insertions(+), 4 deletions(-) > > diff --git a/arch/arm/mach-tegra/cpuidle-tegra114.c b/arch/arm/mach-tegra/cpuidle-tegra114.c > index 155807f..7e59ac0 100644 > --- a/arch/arm/mach-tegra/cpuidle-tegra114.c > +++ b/arch/arm/mach-tegra/cpuidle-tegra114.c > @@ -44,16 +44,12 @@ static int tegra114_idle_power_down(struct cpuidle_device *dev, > tegra_set_cpu_in_lp2(); > cpu_pm_enter(); > > - tick_broadcast_enter(); > - > call_firmware_op(prepare_idle); > > /* Do suspend by ourselves if the firmware does not implement it */ > if (call_firmware_op(do_idle, 0) == -ENOSYS) > cpu_suspend(0, tegra30_sleep_cpu_secondary_finish); > > - tick_broadcast_exit(); > - > cpu_pm_exit(); > tegra_clear_cpu_in_lp2(); > > @@ -61,6 +57,13 @@ static int tegra114_idle_power_down(struct cpuidle_device *dev, > > return index; > } > + > +static void tegra114_idle_enter_freeze(struct cpuidle_device *dev, > + struct cpuidle_driver *drv, > + int index) > +{ > + tegra114_idle_power_down(dev, drv, index); > +} You do not need this function, remove it and update the enter_freeze pointer below with tegra114_idle_power_down please. Thanks, Lorenzo > #endif > > static struct cpuidle_driver tegra_idle_driver = { > @@ -72,8 +75,10 @@ static struct cpuidle_driver tegra_idle_driver = { > #ifdef CONFIG_PM_SLEEP > [1] = { > .enter = tegra114_idle_power_down, > + .enter_freeze = tegra114_idle_enter_freeze, > .exit_latency = 500, > .target_residency = 1000, > + .flags = CPUIDLE_FLAG_TIMER_STOP, > .power_usage = 0, > .name = "powered-down", > .desc = "CPU power gated", > -- > 2.4.1 >