cpuidle: tegra: Correctly handle result of arm_cpuidle_simple_enter() (1170433e) · Commits · 戴 / test

The enter() callback of CPUIDLE drivers returns index of the entered idle state on success or a negative value on failure. The negative value could any negative value, i.e. it doesn't necessarily needs to be a error code. That's because CPUIDLE core only cares about the fact of failure and not about the reason of the enter() failure. Like every other enter() callback, the arm_cpuidle_simple_enter() returns the entered idle-index on success. Unlike some of other drivers, it never fails. It happened that TEGRA_C1=index=err=0 in the code of cpuidle-tegra driver, and thus, there is no problem for the cpuidle-tegra driver created by the typo in the code which assumes that the arm_cpuidle_simple_enter() returns a error code. The arm_cpuidle_simple_enter() also may return a -ENODEV error if CPU_IDLE is disabled in a kernel's config, but all CPUIDLE drivers are disabled if CPU_IDLE is disabled, including the cpuidle-tegra driver. So we can't ever see the error code from arm_cpuidle_simple_enter() today. Of course the code may get some changes in the future and then the typo may transform into a real bug, so let's correct the typo! The tegra_cpuidle_state_enter() is now changed to make it return the entered idle-index on success and negative error code on fail, which puts it on par with the arm_cpuidle_simple_enter(), making code consistent in regards to the error handling. This patch fixes a minor typo in the code, it doesn't fix any bugs. Signed-off-by:

Dmitry Osipenko <digetx@gmail.com> Reviewed-by:

Jon Hunter <jonathanh@nvidia.com> Signed-off-by:

Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/cpuidle/cpuidle-tegra.c

+20 −14

Original line number	Diff line number	Diff line
		@@ -172,7 +172,7 @@ static int tegra_cpuidle_coupled_barrier(struct cpuidle_device *dev)
		static int tegra_cpuidle_state_enter(struct cpuidle_device *dev,
		int index, unsigned int cpu)
		{
		int ret;
		int err;

		/*
		* CC6 state is the "CPU cluster power-off" state. In order to
		@@ -183,9 +183,9 @@ static int tegra_cpuidle_state_enter(struct cpuidle_device *dev,
		* CPU cores, GIC and L2 cache).
		*/
		if (index == TEGRA_CC6) {
		ret = tegra_cpuidle_coupled_barrier(dev);
		if (ret)
		return ret;
		err = tegra_cpuidle_coupled_barrier(dev);
		if (err)
		return err;
		}

		local_fiq_disable();
		@@ -194,15 +194,15 @@ static int tegra_cpuidle_state_enter(struct cpuidle_device *dev,

		switch (index) {
		case TEGRA_C7:
		ret = tegra_cpuidle_c7_enter();
		err = tegra_cpuidle_c7_enter();
		break;

		case TEGRA_CC6:
		ret = tegra_cpuidle_cc6_enter(cpu);
		err = tegra_cpuidle_cc6_enter(cpu);
		break;

		default:
		ret = -EINVAL;
		err = -EINVAL;
		break;
		}

		@@ -210,7 +210,7 @@ static int tegra_cpuidle_state_enter(struct cpuidle_device *dev,
		tegra_pm_clear_cpu_in_lp2();
		local_fiq_enable();

		return ret;
		return err ?: index;
		}

		static int tegra_cpuidle_adjust_state_index(int index, unsigned int cpu)
		@@ -236,21 +236,27 @@ static int tegra_cpuidle_enter(struct cpuidle_device *dev,
		int index)
		{
		unsigned int cpu = cpu_logical_map(dev->cpu);
		int err;
		int ret;

		index = tegra_cpuidle_adjust_state_index(index, cpu);
		if (dev->states_usage[index].disable)
		return -1;

		if (index == TEGRA_C1)
		err = arm_cpuidle_simple_enter(dev, drv, index);
		ret = arm_cpuidle_simple_enter(dev, drv, index);
		else
		err = tegra_cpuidle_state_enter(dev, index, cpu);
		ret = tegra_cpuidle_state_enter(dev, index, cpu);

		if (err && (err != -EINTR \|\| index != TEGRA_CC6))
		pr_err_once("failed to enter state %d err: %d\n", index, err);
		if (ret < 0) {
		if (ret != -EINTR \|\| index != TEGRA_CC6)
		pr_err_once("failed to enter state %d err: %d\n",
		index, ret);
		index = -1;
		} else {
		index = ret;
		}

		return err ? -1 : index;
		return index;
		}

		static int tegra114_enter_s2idle(struct cpuidle_device *dev,

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