Revert "ACPI / sleep: Ignore spurious SCI wakeups from suspend-to-idle"

Revert commit eed4d47efe95 (ACPI / sleep: Ignore spurious SCI wakeups
from suspend-to-idle) as it turned out to be premature and triggered
a number of different issues on various systems.

That includes, but is not limited to, premature suspend-to-RAM aborts
on Dell XPS 13 (9343) reported by Dominik.

The issue the commit in question attempted to address is real and
will need to be taken care of going forward, but evidently more work
is needed for this purpose.

Reported-by: Dominik Brodowski <[e-mail]>
Signed-off-by: Rafael J. Wysocki <[e-mail]>

drivers/acpi/battery.c

···
 	if ((battery->state & ACPI_BATTERY_STATE_CRITICAL) ||
 	    (test_bit(ACPI_BATTERY_ALARM_PRESENT, &battery->flags) &&
             (battery->capacity_now <= battery->alarm)))
-		pm_wakeup_hard_event(&battery->device->dev);
+		pm_wakeup_event(&battery->device->dev, 0);
 
 	return result;
 }

drivers/acpi/button.c

···
 	}
 
 	if (state)
-		pm_wakeup_hard_event(&device->dev);
+		pm_wakeup_event(&device->dev, 0);
 
 	ret = blocking_notifier_call_chain(&acpi_lid_notifier, state, device);
 	if (ret == NOTIFY_DONE)
···
 		} else {
 			int keycode;
 
-			pm_wakeup_hard_event(&device->dev);
+			pm_wakeup_event(&device->dev, 0);
 			if (button->suspended)
 				break;
 
···
 		lid_device = device;
 	}
 
-	device_init_wakeup(&device->dev, true);
 	printk(KERN_INFO PREFIX "%s [%s]\n", name, acpi_device_bid(device));
 	return 0;
 

drivers/acpi/device_pm.c

···
 #include <linux/pm_qos.h>
 #include <linux/pm_domain.h>
 #include <linux/pm_runtime.h>
-#include <linux/suspend.h>
 
 #include "internal.h"
 
···
 	mutex_lock(&acpi_pm_notifier_lock);
 
 	if (adev->wakeup.flags.notifier_present) {
-		pm_wakeup_ws_event(adev->wakeup.ws, 0, true);
+		__pm_wakeup_event(adev->wakeup.ws, 0);
 		if (adev->wakeup.context.work.func)
 			queue_pm_work(&adev->wakeup.context.work);
 	}

drivers/acpi/sleep.c

···
 	acpi_os_wait_events_complete();
 	if (acpi_sci_irq_valid())
 		enable_irq_wake(acpi_sci_irq);
-
 	return 0;
-}
-
-static void acpi_freeze_wake(void)
-{
-	/*
-	 * If IRQD_WAKEUP_ARMED is not set for the SCI at this point, it means
-	 * that the SCI has triggered while suspended, so cancel the wakeup in
-	 * case it has not been a wakeup event (the GPEs will be checked later).
-	 */
-	if (acpi_sci_irq_valid() &&
-	    !irqd_is_wakeup_armed(irq_get_irq_data(acpi_sci_irq)))
-		pm_system_cancel_wakeup();
-}
-
-static void acpi_freeze_sync(void)
-{
-	/*
-	 * Process all pending events in case there are any wakeup ones.
-	 *
-	 * The EC driver uses the system workqueue, so that one needs to be
-	 * flushed too.
-	 */
-	acpi_os_wait_events_complete();
-	flush_scheduled_work();
 }
 
 static void acpi_freeze_restore(void)
···
 	acpi_disable_wakeup_devices(ACPI_STATE_S0);
 	if (acpi_sci_irq_valid())
 		disable_irq_wake(acpi_sci_irq);
-
 	acpi_enable_all_runtime_gpes();
 }
 
···
 static const struct platform_freeze_ops acpi_freeze_ops = {
 	.begin = acpi_freeze_begin,
 	.prepare = acpi_freeze_prepare,
-	.wake = acpi_freeze_wake,
-	.sync = acpi_freeze_sync,
 	.restore = acpi_freeze_restore,
 	.end = acpi_freeze_end,
 };

drivers/base/power/main.c

···
 	if (async_error)
 		goto Complete;
 
+	if (pm_wakeup_pending()) {
+		async_error = -EBUSY;
+		goto Complete;
+	}
+
 	if (dev->power.syscore || dev->power.direct_complete)
 		goto Complete;
 

drivers/base/power/wakeup.c

···
 /* First wakeup IRQ seen by the kernel in the last cycle. */
 unsigned int pm_wakeup_irq __read_mostly;
 
-/* If greater than 0 and the system is suspending, terminate the suspend. */
-static atomic_t pm_abort_suspend __read_mostly;
+/* If set and the system is suspending, terminate the suspend. */
+static bool pm_abort_suspend __read_mostly;
 
 /*
  * Combined counters of registered wakeup events and wakeup events in progress.
···
 		pm_print_active_wakeup_sources();
 	}
 
-	return ret || atomic_read(&pm_abort_suspend) > 0;
+	return ret || pm_abort_suspend;
 }
 
 void pm_system_wakeup(void)
 {
-	atomic_inc(&pm_abort_suspend);
+	pm_abort_suspend = true;
 	freeze_wake();
 }
 EXPORT_SYMBOL_GPL(pm_system_wakeup);
 
-void pm_system_cancel_wakeup(void)
+void pm_wakeup_clear(void)
 {
-	atomic_dec(&pm_abort_suspend);
-}
-
-void pm_wakeup_clear(bool reset)
-{
+	pm_abort_suspend = false;
 	pm_wakeup_irq = 0;
-	if (reset)
-		atomic_set(&pm_abort_suspend, 0);
 }
 
 void pm_system_irq_wakeup(unsigned int irq_number)

include/linux/suspend.h

···
 struct platform_freeze_ops {
 	int (*begin)(void);
 	int (*prepare)(void);
-	void (*wake)(void);
-	void (*sync)(void);
 	void (*restore)(void);
 	void (*end)(void);
 };
···
 
 extern bool pm_wakeup_pending(void);
 extern void pm_system_wakeup(void);
-extern void pm_system_cancel_wakeup(void);
-extern void pm_wakeup_clear(bool reset);
+extern void pm_wakeup_clear(void);
 extern void pm_system_irq_wakeup(unsigned int irq_number);
 extern bool pm_get_wakeup_count(unsigned int *count, bool block);
 extern bool pm_save_wakeup_count(unsigned int count);
···
 
 static inline bool pm_wakeup_pending(void) { return false; }
 static inline void pm_system_wakeup(void) {}
-static inline void pm_wakeup_clear(bool reset) {}
+static inline void pm_wakeup_clear(void) {}
 static inline void pm_system_irq_wakeup(unsigned int irq_number) {}
 
 static inline void lock_system_sleep(void) {}

kernel/power/process.c

···
 	if (!pm_freezing)
 		atomic_inc(&system_freezing_cnt);
 
-	pm_wakeup_clear(true);
+	pm_wakeup_clear();
 	pr_info("Freezing user space processes ... ");
 	pm_freezing = true;
 	error = try_to_freeze_tasks(true);

kernel/power/suspend.c

···
 
 static void freeze_enter(void)
 {
-	trace_suspend_resume(TPS("machine_suspend"), PM_SUSPEND_FREEZE, true);
-
 	spin_lock_irq(&suspend_freeze_lock);
 	if (pm_wakeup_pending())
 		goto out;
···
  out:
 	suspend_freeze_state = FREEZE_STATE_NONE;
 	spin_unlock_irq(&suspend_freeze_lock);
-
-	trace_suspend_resume(TPS("machine_suspend"), PM_SUSPEND_FREEZE, false);
-}
-
-static void s2idle_loop(void)
-{
-	do {
-		freeze_enter();
-
-		if (freeze_ops && freeze_ops->wake)
-			freeze_ops->wake();
-
-		dpm_resume_noirq(PMSG_RESUME);
-		if (freeze_ops && freeze_ops->sync)
-			freeze_ops->sync();
-
-		if (pm_wakeup_pending())
-			break;
-
-		pm_wakeup_clear(false);
-	} while (!dpm_suspend_noirq(PMSG_SUSPEND));
 }
 
 void freeze_wake(void)
···
 	 * all the devices are suspended.
 	 */
 	if (state == PM_SUSPEND_FREEZE) {
-		s2idle_loop();
-		goto Platform_early_resume;
+		trace_suspend_resume(TPS("machine_suspend"), state, true);
+		freeze_enter();
+		trace_suspend_resume(TPS("machine_suspend"), state, false);
+		goto Platform_wake;
 	}
 
 	error = disable_nonboot_cpus();