ARM: OMAP2+: Handle errors for cpu_pm

We need to check for errors when calling cpu_pm_enter() and
cpu_cluster_pm_enter(). And we need to bail out on errors as
otherwise we can enter a deeper idle state when not desired.

I'm not aware of the lack of error handling causing issues yet,
but we need this at least for blocking deeper idle states when
a GPIO instance has pending interrupts.

Cc: Dave Gerlach <d-gerlach@ti.com>
Cc: Grygorii Strashko <grygorii.strashko@ti.com>
Cc: Keerthy <j-keerthy@ti.com>
Cc: Ladislav Michl <ladis@linux-mips.org>
Cc: Russell King <rmk+kernel@armlinux.org.uk>
Cc: Tero Kristo <t-kristo@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Link: https://lore.kernel.org/r/20200304225433.37336-2-tony@atomide.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

arch/arm/mach-omap2/cpuidle34xx.c

@@ -109,6 +109,7 @@ static int omap3_enter_idle(struct cpuidle_device *dev,
 			    int index)
 {
 	struct omap3_idle_statedata *cx = &omap3_idle_data[index];
+	int error;
 
 	if (omap_irq_pending() || need_resched())
 		goto return_sleep_time;
@@ -125,8 +126,11 @@ static int omap3_enter_idle(struct cpuidle_device *dev,
 	 * Call idle CPU PM enter notifier chain so that
 	 * VFP context is saved.
 	 */
-	if (cx->mpu_state == PWRDM_POWER_OFF)
+	if (cx->mpu_state == PWRDM_POWER_OFF) {
-		cpu_pm_enter();
+		error = cpu_pm_enter();
+		if (error)
+			goto out_clkdm_set;
+	}
 
 	/* Execute ARM wfi */
 	omap_sram_idle();
@@ -139,6 +143,7 @@ static int omap3_enter_idle(struct cpuidle_device *dev,
 	    pwrdm_read_prev_pwrst(mpu_pd) == PWRDM_POWER_OFF)
 		cpu_pm_exit();
 
+out_clkdm_set:
 	/* Re-allow idle for C1 */
 	if (cx->flags & OMAP_CPUIDLE_CX_NO_CLKDM_IDLE)
 		clkdm_allow_idle(mpu_pd->pwrdm_clkdms[0]);

arch/arm/mach-omap2/cpuidle44xx.c

@@ -122,6 +122,7 @@ static int omap_enter_idle_coupled(struct cpuidle_device *dev,
 {
 	struct idle_statedata *cx = state_ptr + index;
 	u32 mpuss_can_lose_context = 0;
+	int error;
 
 	/*
 	 * CPU0 has to wait and stay ON until CPU1 is OFF state.
@@ -159,7 +160,9 @@ static int omap_enter_idle_coupled(struct cpuidle_device *dev,
 	 * Call idle CPU PM enter notifier chain so that
 	 * VFP and per CPU interrupt context is saved.
 	 */
-	cpu_pm_enter();
+	error = cpu_pm_enter();
+	if (error)
+		goto cpu_pm_out;
 
 	if (dev->cpu == 0) {
 		pwrdm_set_logic_retst(mpu_pd, cx->mpu_logic_state);
@@ -169,13 +172,17 @@ static int omap_enter_idle_coupled(struct cpuidle_device *dev,
 		 * Call idle CPU cluster PM enter notifier chain
 		 * to save GIC and wakeupgen context.
 		 */
-		if (mpuss_can_lose_context)
+		if (mpuss_can_lose_context) {
-			cpu_cluster_pm_enter();
+			error = cpu_cluster_pm_enter();
+			if (error)
+				goto cpu_cluster_pm_out;
+		}
 	}
 
 	omap4_enter_lowpower(dev->cpu, cx->cpu_state);
 	cpu_done[dev->cpu] = true;
 
+cpu_cluster_pm_out:
 	/* Wakeup CPU1 only if it is not offlined */
 	if (dev->cpu == 0 && cpumask_test_cpu(1, cpu_online_mask)) {
 
@@ -197,12 +204,6 @@ static int omap_enter_idle_coupled(struct cpuidle_device *dev,
 		}
 	}
 
-	/*
-	 * Call idle CPU PM exit notifier chain to restore
-	 * VFP and per CPU IRQ context.
-	 */
-	cpu_pm_exit();
-
 	/*
 	 * Call idle CPU cluster PM exit notifier chain
 	 * to restore GIC and wakeupgen context.
@@ -210,6 +211,13 @@ static int omap_enter_idle_coupled(struct cpuidle_device *dev,
 	if (dev->cpu == 0 && mpuss_can_lose_context)
 		cpu_cluster_pm_exit();
 
+	/*
+	 * Call idle CPU PM exit notifier chain to restore
+	 * VFP and per CPU IRQ context.
+	 */
+	cpu_pm_exit();
+
+cpu_pm_out:
 	tick_broadcast_exit();
 
 fail:

arch/arm/mach-omap2/pm34xx.c

@@ -191,6 +191,7 @@ void omap_sram_idle(void)
 	int per_next_state = PWRDM_POWER_ON;
 	int core_next_state = PWRDM_POWER_ON;
 	u32 sdrc_pwr = 0;
+	int error;
 
 	mpu_next_state = pwrdm_read_next_pwrst(mpu_pwrdm);
 	switch (mpu_next_state) {
@@ -219,8 +220,11 @@ void omap_sram_idle(void)
 	pwrdm_pre_transition(NULL);
 
 	/* PER */
-	if (per_next_state == PWRDM_POWER_OFF)
+	if (per_next_state == PWRDM_POWER_OFF) {
-		cpu_cluster_pm_enter();
+		error = cpu_cluster_pm_enter();
+		if (error)
+			return;
+	}
 
 	/* CORE */
 	if (core_next_state < PWRDM_POWER_ON) {