ARM: tegra: Propagate error from tegra_idle_lp2_last()

Technically cpu_suspend() may fail and it's never good to lose information
about failure. For example things like cpuidle core could correctly sample
idling time in the case of failure.
Acked-by: Peter De Schrijver <pdeschrijver@nvidia.com>
Tested-by: Peter Geis <pgwipeout@gmail.com>
Tested-by: Jasper Korten <jja2000@gmail.com>
Tested-by: David Heidelberg <david@ixit.cz>
Tested-by: Nicolas Chauvet <kwizart@gmail.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

arch/arm/mach-tegra/cpuidle-tegra20.c

@@ -86,15 +86,17 @@ static bool tegra20_cpu_cluster_power_down(struct cpuidle_device *dev,
 					   struct cpuidle_driver *drv,
 					   int index)
 {
+	bool ret;
+
 	while (!tegra_cpu_rail_off_ready())
 		cpu_relax();
 
-	tegra_idle_lp2_last();
+	ret = !tegra_idle_lp2_last();
 
 	if (cpu_online(1))
 		tegra20_wake_cpu1_from_reset();
 
-	return true;
+	return ret;
 }
 
 #ifdef CONFIG_SMP

arch/arm/mach-tegra/cpuidle-tegra30.c

@@ -68,9 +68,7 @@ static bool tegra30_cpu_cluster_power_down(struct cpuidle_device *dev,
 		return false;
 	}
 
-	tegra_idle_lp2_last();
-
-	return true;
+	return !tegra_idle_lp2_last();
 }
 
 #ifdef CONFIG_SMP

arch/arm/mach-tegra/pm.c

@@ -189,14 +189,16 @@ static void tegra_pm_set(enum tegra_suspend_mode mode)
 	tegra_pmc_enter_suspend_mode(mode);
 }
 
-void tegra_idle_lp2_last(void)
+int tegra_idle_lp2_last(void)
 {
+	int err;
+
 	tegra_pm_set(TEGRA_SUSPEND_LP2);
 
 	cpu_cluster_pm_enter();
 	suspend_cpu_complex();
 
-	cpu_suspend(PHYS_OFFSET - PAGE_OFFSET, &tegra_sleep_cpu);
+	err = cpu_suspend(PHYS_OFFSET - PAGE_OFFSET, &tegra_sleep_cpu);
 
 	/*
 	 * Resume L2 cache if it wasn't re-enabled early during resume,
@@ -208,6 +210,8 @@ void tegra_idle_lp2_last(void)
 
 	restore_cpu_complex();
 	cpu_cluster_pm_exit();
+
+	return err;
 }
 
 enum tegra_suspend_mode tegra_pm_validate_suspend_mode(

arch/arm/mach-tegra/pm.h

@@ -25,7 +25,7 @@ void tegra30_sleep_core_init(void);
 
 void tegra_clear_cpu_in_lp2(void);
 void tegra_set_cpu_in_lp2(void);
-void tegra_idle_lp2_last(void);
+int tegra_idle_lp2_last(void);
 extern void (*tegra_tear_down_cpu)(void);
 
 #ifdef CONFIG_PM_SLEEP