Merge branch 'pm-genirq' into acpi-pm

Documentation/power/suspend-and-interrupts.txt

@@ -0,0 +1,123 @@
+System Suspend and Device Interrupts
+
+Copyright (C) 2014 Intel Corp.
+Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
+
+
+Suspending and Resuming Device IRQs
+-----------------------------------
+
+Device interrupt request lines (IRQs) are generally disabled during system
+suspend after the "late" phase of suspending devices (that is, after all of the
+->prepare, ->suspend and ->suspend_late callbacks have been executed for all
+devices).  That is done by suspend_device_irqs().
+
+The rationale for doing so is that after the "late" phase of device suspend
+there is no legitimate reason why any interrupts from suspended devices should
+trigger and if any devices have not been suspended properly yet, it is better to
+block interrupts from them anyway.  Also, in the past we had problems with
+interrupt handlers for shared IRQs that device drivers implementing them were
+not prepared for interrupts triggering after their devices had been suspended.
+In some cases they would attempt to access, for example, memory address spaces
+of suspended devices and cause unpredictable behavior to ensue as a result.
+Unfortunately, such problems are very difficult to debug and the introduction
+of suspend_device_irqs(), along with the "noirq" phase of device suspend and
+resume, was the only practical way to mitigate them.
+
+Device IRQs are re-enabled during system resume, right before the "early" phase
+of resuming devices (that is, before starting to execute ->resume_early
+callbacks for devices).  The function doing that is resume_device_irqs().
+
+
+The IRQF_NO_SUSPEND Flag
+------------------------
+
+There are interrupts that can legitimately trigger during the entire system
+suspend-resume cycle, including the "noirq" phases of suspending and resuming
+devices as well as during the time when nonboot CPUs are taken offline and
+brought back online.  That applies to timer interrupts in the first place,
+but also to IPIs and to some other special-purpose interrupts.
+
+The IRQF_NO_SUSPEND flag is used to indicate that to the IRQ subsystem when
+requesting a special-purpose interrupt.  It causes suspend_device_irqs() to
+leave the corresponding IRQ enabled so as to allow the interrupt to work all
+the time as expected.
+
+Note that the IRQF_NO_SUSPEND flag affects the entire IRQ and not just one
+user of it.  Thus, if the IRQ is shared, all of the interrupt handlers installed
+for it will be executed as usual after suspend_device_irqs(), even if the
+IRQF_NO_SUSPEND flag was not passed to request_irq() (or equivalent) by some of
+the IRQ's users.  For this reason, using IRQF_NO_SUSPEND and IRQF_SHARED at the
+same time should be avoided.
+
+
+System Wakeup Interrupts, enable_irq_wake() and disable_irq_wake()
+------------------------------------------------------------------
+
+System wakeup interrupts generally need to be configured to wake up the system
+from sleep states, especially if they are used for different purposes (e.g. as
+I/O interrupts) in the working state.
+
+That may involve turning on a special signal handling logic within the platform
+(such as an SoC) so that signals from a given line are routed in a different way
+during system sleep so as to trigger a system wakeup when needed.  For example,
+the platform may include a dedicated interrupt controller used specifically for
+handling system wakeup events.  Then, if a given interrupt line is supposed to
+wake up the system from sleep sates, the corresponding input of that interrupt
+controller needs to be enabled to receive signals from the line in question.
+After wakeup, it generally is better to disable that input to prevent the
+dedicated controller from triggering interrupts unnecessarily.
+
+The IRQ subsystem provides two helper functions to be used by device drivers for
+those purposes.  Namely, enable_irq_wake() turns on the platform's logic for
+handling the given IRQ as a system wakeup interrupt line and disable_irq_wake()
+turns that logic off.
+
+Calling enable_irq_wake() causes suspend_device_irqs() to treat the given IRQ
+in a special way.  Namely, the IRQ remains enabled, by on the first interrupt
+it will be disabled, marked as pending and "suspended" so that it will be
+re-enabled by resume_device_irqs() during the subsequent system resume.  Also
+the PM core is notified about the event which casues the system suspend in
+progress to be aborted (that doesn't have to happen immediately, but at one
+of the points where the suspend thread looks for pending wakeup events).
+
+This way every interrupt from a wakeup interrupt source will either cause the
+system suspend currently in progress to be aborted or wake up the system if
+already suspended.  However, after suspend_device_irqs() interrupt handlers are
+not executed for system wakeup IRQs.  They are only executed for IRQF_NO_SUSPEND
+IRQs at that time, but those IRQs should not be configured for system wakeup
+using enable_irq_wake().
+
+
+Interrupts and Suspend-to-Idle
+------------------------------
+
+Suspend-to-idle (also known as the "freeze" sleep state) is a relatively new
+system sleep state that works by idling all of the processors and waiting for
+interrupts right after the "noirq" phase of suspending devices.
+
+Of course, this means that all of the interrupts with the IRQF_NO_SUSPEND flag
+set will bring CPUs out of idle while in that state, but they will not cause the
+IRQ subsystem to trigger a system wakeup.
+
+System wakeup interrupts, in turn, will trigger wakeup from suspend-to-idle in
+analogy with what they do in the full system suspend case.  The only difference
+is that the wakeup from suspend-to-idle is signaled using the usual working
+state interrupt delivery mechanisms and doesn't require the platform to use
+any special interrupt handling logic for it to work.
+
+
+IRQF_NO_SUSPEND and enable_irq_wake()
+-------------------------------------
+
+There are no valid reasons to use both enable_irq_wake() and the IRQF_NO_SUSPEND
+flag on the same IRQ.
+
+First of all, if the IRQ is not shared, the rules for handling IRQF_NO_SUSPEND
+interrupts (interrupt handlers are invoked after suspend_device_irqs()) are
+directly at odds with the rules for handling system wakeup interrupts (interrupt
+handlers are not invoked after suspend_device_irqs()).
+
+Second, both enable_irq_wake() and IRQF_NO_SUSPEND apply to entire IRQs and not
+to individual interrupt handlers, so sharing an IRQ between a system wakeup
+interrupt source and an IRQF_NO_SUSPEND interrupt source does not make sense.

arch/x86/kernel/apic/io_apic.c

@@ -2623,6 +2623,7 @@ static struct irq_chip ioapic_chip __read_mostly = {
 	.irq_eoi		= ack_apic_level,
 	.irq_set_affinity	= native_ioapic_set_affinity,
 	.irq_retrigger		= ioapic_retrigger_irq,
+	.flags			= IRQCHIP_SKIP_SET_WAKE,
 };
 
 static inline void init_IO_APIC_traps(void)
@@ -3173,6 +3174,7 @@ static struct irq_chip msi_chip = {
 	.irq_ack		= ack_apic_edge,
 	.irq_set_affinity	= msi_set_affinity,
 	.irq_retrigger		= ioapic_retrigger_irq,
+	.flags			= IRQCHIP_SKIP_SET_WAKE,
 };
 
 int setup_msi_irq(struct pci_dev *dev, struct msi_desc *msidesc,
@@ -3271,6 +3273,7 @@ static struct irq_chip dmar_msi_type = {
 	.irq_ack		= ack_apic_edge,
 	.irq_set_affinity	= dmar_msi_set_affinity,
 	.irq_retrigger		= ioapic_retrigger_irq,
+	.flags			= IRQCHIP_SKIP_SET_WAKE,
 };
 
 int arch_setup_dmar_msi(unsigned int irq)
@@ -3321,6 +3324,7 @@ static struct irq_chip hpet_msi_type = {
 	.irq_ack = ack_apic_edge,
 	.irq_set_affinity = hpet_msi_set_affinity,
 	.irq_retrigger = ioapic_retrigger_irq,
+	.flags = IRQCHIP_SKIP_SET_WAKE,
 };
 
 int default_setup_hpet_msi(unsigned int irq, unsigned int id)
@@ -3384,6 +3388,7 @@ static struct irq_chip ht_irq_chip = {
 	.irq_ack		= ack_apic_edge,
 	.irq_set_affinity	= ht_set_affinity,
 	.irq_retrigger		= ioapic_retrigger_irq,
+	.flags			= IRQCHIP_SKIP_SET_WAKE,
 };
 
 int arch_setup_ht_irq(unsigned int irq, struct pci_dev *dev)

drivers/base/power/wakeup.c

@@ -24,6 +24,9 @@
  */
 bool events_check_enabled __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.
  * They need to be modified together atomically, so it's better to use one
@@ -719,7 +722,18 @@ bool pm_wakeup_pending(void)
 		pm_print_active_wakeup_sources();
 	}
 
-	return ret;
+	return ret || pm_abort_suspend;
+}
+
+void pm_system_wakeup(void)
+{
+	pm_abort_suspend = true;
+	freeze_wake();
+}
+
+void pm_wakeup_clear(void)
+{
+	pm_abort_suspend = false;
 }
 
 /**

drivers/base/syscore.c

@@ -9,7 +9,7 @@
 #include <linux/syscore_ops.h>
 #include <linux/mutex.h>
 #include <linux/module.h>
-#include <linux/interrupt.h>
+#include <linux/suspend.h>
 #include <trace/events/power.h>
 
 static LIST_HEAD(syscore_ops_list);
@@ -54,9 +54,8 @@ int syscore_suspend(void)
 	pr_debug("Checking wakeup interrupts\n");
 
 	/* Return error code if there are any wakeup interrupts pending. */
-	ret = check_wakeup_irqs();
-	if (ret)
-		return ret;
+	if (pm_wakeup_pending())
+		return -EBUSY;
 
 	WARN_ONCE(!irqs_disabled(),
 		"Interrupts enabled before system core suspend.\n");

drivers/pci/pcie/pme.c

@@ -41,11 +41,17 @@ static int __init pcie_pme_setup(char *str)
 }
 __setup("pcie_pme=", pcie_pme_setup);
 
+enum pme_suspend_level {
+	PME_SUSPEND_NONE = 0,
+	PME_SUSPEND_WAKEUP,
+	PME_SUSPEND_NOIRQ,
+};
+
 struct pcie_pme_service_data {
 	spinlock_t lock;
 	struct pcie_device *srv;
 	struct work_struct work;
-	bool noirq; /* Don't enable the PME interrupt used by this service. */
+	enum pme_suspend_level suspend_level;
 };
 
 /**
@@ -223,7 +229,7 @@ static void pcie_pme_work_fn(struct work_struct *work)
 	spin_lock_irq(&data->lock);
 
 	for (;;) {
-		if (data->noirq)
+		if (data->suspend_level != PME_SUSPEND_NONE)
 			break;
 
 		pcie_capability_read_dword(port, PCI_EXP_RTSTA, &rtsta);
@@ -250,7 +256,7 @@ static void pcie_pme_work_fn(struct work_struct *work)
 		spin_lock_irq(&data->lock);
 	}
 
-	if (!data->noirq)
+	if (data->suspend_level == PME_SUSPEND_NONE)
 		pcie_pme_interrupt_enable(port, true);
 
 	spin_unlock_irq(&data->lock);
@@ -367,6 +373,21 @@ static int pcie_pme_probe(struct pcie_device *srv)
 	return ret;
 }
 
+static bool pcie_pme_check_wakeup(struct pci_bus *bus)
+{
+	struct pci_dev *dev;
+
+	if (!bus)
+		return false;
+
+	list_for_each_entry(dev, &bus->devices, bus_list)
+		if (device_may_wakeup(&dev->dev)
+		    || pcie_pme_check_wakeup(dev->subordinate))
+			return true;
+
+	return false;
+}
+
 /**
  * pcie_pme_suspend - Suspend PCIe PME service device.
  * @srv: PCIe service device to suspend.
@@ -375,11 +396,26 @@ static int pcie_pme_suspend(struct pcie_device *srv)
 {
 	struct pcie_pme_service_data *data = get_service_data(srv);
 	struct pci_dev *port = srv->port;
+	bool wakeup;
 
+	if (device_may_wakeup(&port->dev)) {
+		wakeup = true;
+	} else {
+		down_read(&pci_bus_sem);
+		wakeup = pcie_pme_check_wakeup(port->subordinate);
+		up_read(&pci_bus_sem);
+	}
 	spin_lock_irq(&data->lock);
-	pcie_pme_interrupt_enable(port, false);
-	pcie_clear_root_pme_status(port);
-	data->noirq = true;
+	if (wakeup) {
+		enable_irq_wake(srv->irq);
+		data->suspend_level = PME_SUSPEND_WAKEUP;
+	} else {
+		struct pci_dev *port = srv->port;
+
+		pcie_pme_interrupt_enable(port, false);
+		pcie_clear_root_pme_status(port);
+		data->suspend_level = PME_SUSPEND_NOIRQ;
+	}
 	spin_unlock_irq(&data->lock);
 
 	synchronize_irq(srv->irq);
@@ -394,12 +430,17 @@ static int pcie_pme_suspend(struct pcie_device *srv)
 static int pcie_pme_resume(struct pcie_device *srv)
 {
 	struct pcie_pme_service_data *data = get_service_data(srv);
-	struct pci_dev *port = srv->port;
 
 	spin_lock_irq(&data->lock);
-	data->noirq = false;
-	pcie_clear_root_pme_status(port);
-	pcie_pme_interrupt_enable(port, true);
+	if (data->suspend_level == PME_SUSPEND_NOIRQ) {
+		struct pci_dev *port = srv->port;
+
+		pcie_clear_root_pme_status(port);
+		pcie_pme_interrupt_enable(port, true);
+	} else {
+		disable_irq_wake(srv->irq);
+	}
+	data->suspend_level = PME_SUSPEND_NONE;
 	spin_unlock_irq(&data->lock);
 
 	return 0;

include/linux/interrupt.h

@@ -193,11 +193,6 @@ extern void irq_wake_thread(unsigned int irq, void *dev_id);
 /* The following three functions are for the core kernel use only. */
 extern void suspend_device_irqs(void);
 extern void resume_device_irqs(void);
-#ifdef CONFIG_PM_SLEEP
-extern int check_wakeup_irqs(void);
-#else
-static inline int check_wakeup_irqs(void) { return 0; }
-#endif
 
 /**
  * struct irq_affinity_notify - context for notification of IRQ affinity changes

include/linux/irq.h

@@ -173,6 +173,7 @@ struct irq_data {
  * IRQD_IRQ_DISABLED		- Disabled state of the interrupt
  * IRQD_IRQ_MASKED		- Masked state of the interrupt
  * IRQD_IRQ_INPROGRESS		- In progress state of the interrupt
+ * IRQD_WAKEUP_ARMED		- Wakeup mode armed
  */
 enum {
 	IRQD_TRIGGER_MASK		= 0xf,
@@ -186,6 +187,7 @@ enum {
 	IRQD_IRQ_DISABLED		= (1 << 16),
 	IRQD_IRQ_MASKED			= (1 << 17),
 	IRQD_IRQ_INPROGRESS		= (1 << 18),
+	IRQD_WAKEUP_ARMED		= (1 << 19),
 };
 
 static inline bool irqd_is_setaffinity_pending(struct irq_data *d)
@@ -257,6 +259,12 @@ static inline bool irqd_irq_inprogress(struct irq_data *d)
 	return d->state_use_accessors & IRQD_IRQ_INPROGRESS;
 }
 
+static inline bool irqd_is_wakeup_armed(struct irq_data *d)
+{
+	return d->state_use_accessors & IRQD_WAKEUP_ARMED;
+}
+
+
 /*
  * Functions for chained handlers which can be enabled/disabled by the
  * standard disable_irq/enable_irq calls. Must be called with

include/linux/irqdesc.h

@@ -36,6 +36,11 @@ struct irq_desc;
  * @threads_oneshot:	bitfield to handle shared oneshot threads
  * @threads_active:	number of irqaction threads currently running
  * @wait_for_threads:	wait queue for sync_irq to wait for threaded handlers
+ * @nr_actions:		number of installed actions on this descriptor
+ * @no_suspend_depth:	number of irqactions on a irq descriptor with
+ *			IRQF_NO_SUSPEND set
+ * @force_resume_depth:	number of irqactions on a irq descriptor with
+ *			IRQF_FORCE_RESUME set
  * @dir:		/proc/irq/ procfs entry
  * @name:		flow handler name for /proc/interrupts output
  */
@@ -68,6 +73,11 @@ struct irq_desc {
 	unsigned long		threads_oneshot;
 	atomic_t		threads_active;
 	wait_queue_head_t       wait_for_threads;
+#ifdef CONFIG_PM_SLEEP
+	unsigned int		nr_actions;
+	unsigned int		no_suspend_depth;
+	unsigned int		force_resume_depth;
+#endif
 #ifdef CONFIG_PROC_FS
 	struct proc_dir_entry	*dir;
 #endif

include/linux/suspend.h

@@ -371,6 +371,8 @@ extern int unregister_pm_notifier(struct notifier_block *nb);
 extern bool events_check_enabled;
 
 extern bool pm_wakeup_pending(void);
+extern void pm_system_wakeup(void);
+extern void pm_wakeup_clear(void);
 extern bool pm_get_wakeup_count(unsigned int *count, bool block);
 extern bool pm_save_wakeup_count(unsigned int count);
 extern void pm_wakep_autosleep_enabled(bool set);
@@ -418,6 +420,8 @@ static inline int unregister_pm_notifier(struct notifier_block *nb)
 #define pm_notifier(fn, pri)	do { (void)(fn); } while (0)
 
 static inline bool pm_wakeup_pending(void) { return false; }
+static inline void pm_system_wakeup(void) {}
+static inline void pm_wakeup_clear(void) {}
 
 static inline void lock_system_sleep(void) {}
 static inline void unlock_system_sleep(void) {}

kernel/irq/chip.c

@@ -342,6 +342,31 @@ static bool irq_check_poll(struct irq_desc *desc)
 	return irq_wait_for_poll(desc);
 }
 
+static bool irq_may_run(struct irq_desc *desc)
+{
+	unsigned int mask = IRQD_IRQ_INPROGRESS | IRQD_WAKEUP_ARMED;
+
+	/*
+	 * If the interrupt is not in progress and is not an armed
+	 * wakeup interrupt, proceed.
+	 */
+	if (!irqd_has_set(&desc->irq_data, mask))
+		return true;
+
+	/*
+	 * If the interrupt is an armed wakeup source, mark it pending
+	 * and suspended, disable it and notify the pm core about the
+	 * event.
+	 */
+	if (irq_pm_check_wakeup(desc))
+		return false;
+
+	/*
+	 * Handle a potential concurrent poll on a different core.
+	 */
+	return irq_check_poll(desc);
+}
+
 /**
  *	handle_simple_irq - Simple and software-decoded IRQs.
  *	@irq:	the interrupt number
@@ -359,9 +384,8 @@ handle_simple_irq(unsigned int irq, struct irq_desc *desc)
 {
 	raw_spin_lock(&desc->lock);
 
-	if (unlikely(irqd_irq_inprogress(&desc->irq_data)))
-		if (!irq_check_poll(desc))
-			goto out_unlock;
+	if (!irq_may_run(desc))
+		goto out_unlock;
 
 	desc->istate &= ~(IRQS_REPLAY | IRQS_WAITING);
 	kstat_incr_irqs_this_cpu(irq, desc);
@@ -412,9 +436,8 @@ handle_level_irq(unsigned int irq, struct irq_desc *desc)
 	raw_spin_lock(&desc->lock);
 	mask_ack_irq(desc);
 
-	if (unlikely(irqd_irq_inprogress(&desc->irq_data)))
-		if (!irq_check_poll(desc))
-			goto out_unlock;
+	if (!irq_may_run(desc))
+		goto out_unlock;
 
 	desc->istate &= ~(IRQS_REPLAY | IRQS_WAITING);
 	kstat_incr_irqs_this_cpu(irq, desc);
@@ -485,9 +508,8 @@ handle_fasteoi_irq(unsigned int irq, struct irq_desc *desc)
 
 	raw_spin_lock(&desc->lock);
 
-	if (unlikely(irqd_irq_inprogress(&desc->irq_data)))
-		if (!irq_check_poll(desc))
-			goto out;
+	if (!irq_may_run(desc))
+		goto out;
 
 	desc->istate &= ~(IRQS_REPLAY | IRQS_WAITING);
 	kstat_incr_irqs_this_cpu(irq, desc);
@@ -541,19 +563,23 @@ handle_edge_irq(unsigned int irq, struct irq_desc *desc)
 	raw_spin_lock(&desc->lock);
 
 	desc->istate &= ~(IRQS_REPLAY | IRQS_WAITING);
+
+	if (!irq_may_run(desc)) {
+		desc->istate |= IRQS_PENDING;
+		mask_ack_irq(desc);
+		goto out_unlock;
+	}
+
 	/*
-	 * If we're currently running this IRQ, or its disabled,
-	 * we shouldn't process the IRQ. Mark it pending, handle
-	 * the necessary masking and go out
+	 * If its disabled or no action available then mask it and get
+	 * out of here.
 	 */
-	if (unlikely(irqd_irq_disabled(&desc->irq_data) ||
-		     irqd_irq_inprogress(&desc->irq_data) || !desc->action)) {
-		if (!irq_check_poll(desc)) {
-			desc->istate |= IRQS_PENDING;
-			mask_ack_irq(desc);
-			goto out_unlock;
-		}
+	if (irqd_irq_disabled(&desc->irq_data) || !desc->action) {
+		desc->istate |= IRQS_PENDING;
+		mask_ack_irq(desc);
+		goto out_unlock;
 	}
+
 	kstat_incr_irqs_this_cpu(irq, desc);
 
 	/* Start handling the irq */
@@ -602,18 +628,21 @@ void handle_edge_eoi_irq(unsigned int irq, struct irq_desc *desc)
 	raw_spin_lock(&desc->lock);
 
 	desc->istate &= ~(IRQS_REPLAY | IRQS_WAITING);
+
+	if (!irq_may_run(desc)) {
+		desc->istate |= IRQS_PENDING;
+		goto out_eoi;
+	}
+
 	/*
-	 * If we're currently running this IRQ, or its disabled,
-	 * we shouldn't process the IRQ. Mark it pending, handle
-	 * the necessary masking and go out
+	 * If its disabled or no action available then mask it and get
+	 * out of here.
 	 */
-	if (unlikely(irqd_irq_disabled(&desc->irq_data) ||
-		     irqd_irq_inprogress(&desc->irq_data) || !desc->action)) {
-		if (!irq_check_poll(desc)) {
-			desc->istate |= IRQS_PENDING;
-			goto out_eoi;
-		}
+	if (irqd_irq_disabled(&desc->irq_data) || !desc->action) {
+		desc->istate |= IRQS_PENDING;
+		goto out_eoi;
 	}
+
 	kstat_incr_irqs_this_cpu(irq, desc);
 
 	do {

kernel/irq/internals.h

@@ -63,8 +63,8 @@ enum {
 
 extern int __irq_set_trigger(struct irq_desc *desc, unsigned int irq,
 		unsigned long flags);
-extern void __disable_irq(struct irq_desc *desc, unsigned int irq, bool susp);
-extern void __enable_irq(struct irq_desc *desc, unsigned int irq, bool resume);
+extern void __disable_irq(struct irq_desc *desc, unsigned int irq);
+extern void __enable_irq(struct irq_desc *desc, unsigned int irq);
 
 extern int irq_startup(struct irq_desc *desc, bool resend);
 extern void irq_shutdown(struct irq_desc *desc);
@@ -194,3 +194,15 @@ static inline void kstat_incr_irqs_this_cpu(unsigned int irq, struct irq_desc *d
 	__this_cpu_inc(*desc->kstat_irqs);
 	__this_cpu_inc(kstat.irqs_sum);
 }
+
+#ifdef CONFIG_PM_SLEEP
+bool irq_pm_check_wakeup(struct irq_desc *desc);
+void irq_pm_install_action(struct irq_desc *desc, struct irqaction *action);
+void irq_pm_remove_action(struct irq_desc *desc, struct irqaction *action);
+#else
+static inline bool irq_pm_check_wakeup(struct irq_desc *desc) { return false; }
+static inline void
+irq_pm_install_action(struct irq_desc *desc, struct irqaction *action) { }
+static inline void
+irq_pm_remove_action(struct irq_desc *desc, struct irqaction *action) { }
+#endif

kernel/irq/manage.c

@@ -382,14 +382,8 @@ setup_affinity(unsigned int irq, struct irq_desc *desc, struct cpumask *mask)
 }
 #endif
 
-void __disable_irq(struct irq_desc *desc, unsigned int irq, bool suspend)
+void __disable_irq(struct irq_desc *desc, unsigned int irq)
 {
-	if (suspend) {
-		if (!desc->action || (desc->action->flags & IRQF_NO_SUSPEND))
-			return;
-		desc->istate |= IRQS_SUSPENDED;
-	}
-
 	if (!desc->depth++)
 		irq_disable(desc);
 }
@@ -401,7 +395,7 @@ static int __disable_irq_nosync(unsigned int irq)
 
 	if (!desc)
 		return -EINVAL;
-	__disable_irq(desc, irq, false);
+	__disable_irq(desc, irq);
 	irq_put_desc_busunlock(desc, flags);
 	return 0;
 }
@@ -442,20 +436,8 @@ void disable_irq(unsigned int irq)
 }
 EXPORT_SYMBOL(disable_irq);
 
-void __enable_irq(struct irq_desc *desc, unsigned int irq, bool resume)
+void __enable_irq(struct irq_desc *desc, unsigned int irq)
 {
-	if (resume) {
-		if (!(desc->istate & IRQS_SUSPENDED)) {
-			if (!desc->action)
-				return;
-			if (!(desc->action->flags & IRQF_FORCE_RESUME))
-				return;
-			/* Pretend that it got disabled ! */
-			desc->depth++;
-		}
-		desc->istate &= ~IRQS_SUSPENDED;
-	}
-
 	switch (desc->depth) {
 	case 0:
  err_out:
@@ -497,7 +479,7 @@ void enable_irq(unsigned int irq)
 		 KERN_ERR "enable_irq before setup/request_irq: irq %u\n", irq))
 		goto out;
 
-	__enable_irq(desc, irq, false);
+	__enable_irq(desc, irq);
 out:
 	irq_put_desc_busunlock(desc, flags);
 }
@@ -1218,6 +1200,8 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
 	new->irq = irq;
 	*old_ptr = new;
 
+	irq_pm_install_action(desc, new);
+
 	/* Reset broken irq detection when installing new handler */
 	desc->irq_count = 0;
 	desc->irqs_unhandled = 0;
@@ -1228,7 +1212,7 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
 	 */
 	if (shared && (desc->istate & IRQS_SPURIOUS_DISABLED)) {
 		desc->istate &= ~IRQS_SPURIOUS_DISABLED;
-		__enable_irq(desc, irq, false);
+		__enable_irq(desc, irq);
 	}
 
 	raw_spin_unlock_irqrestore(&desc->lock, flags);
@@ -1336,6 +1320,8 @@ static struct irqaction *__free_irq(unsigned int irq, void *dev_id)
 	/* Found it - now remove it from the list of entries: */
 	*action_ptr = action->next;
 
+	irq_pm_remove_action(desc, action);
+
 	/* If this was the last handler, shut down the IRQ line: */
 	if (!desc->action) {
 		irq_shutdown(desc);

kernel/irq/pm.c

@@ -9,17 +9,105 @@
 #include <linux/irq.h>
 #include <linux/module.h>
 #include <linux/interrupt.h>
+#include <linux/suspend.h>
 #include <linux/syscore_ops.h>
 
 #include "internals.h"
 
+bool irq_pm_check_wakeup(struct irq_desc *desc)
+{
+	if (irqd_is_wakeup_armed(&desc->irq_data)) {
+		irqd_clear(&desc->irq_data, IRQD_WAKEUP_ARMED);
+		desc->istate |= IRQS_SUSPENDED | IRQS_PENDING;
+		desc->depth++;
+		irq_disable(desc);
+		pm_system_wakeup();
+		return true;
+	}
+	return false;
+}
+
+/*
+ * Called from __setup_irq() with desc->lock held after @action has
+ * been installed in the action chain.
+ */
+void irq_pm_install_action(struct irq_desc *desc, struct irqaction *action)
+{
+	desc->nr_actions++;
+
+	if (action->flags & IRQF_FORCE_RESUME)
+		desc->force_resume_depth++;
+
+	WARN_ON_ONCE(desc->force_resume_depth &&
+		     desc->force_resume_depth != desc->nr_actions);
+
+	if (action->flags & IRQF_NO_SUSPEND)
+		desc->no_suspend_depth++;
+
+	WARN_ON_ONCE(desc->no_suspend_depth &&
+		     desc->no_suspend_depth != desc->nr_actions);
+}
+
+/*
+ * Called from __free_irq() with desc->lock held after @action has
+ * been removed from the action chain.
+ */
+void irq_pm_remove_action(struct irq_desc *desc, struct irqaction *action)
+{
+	desc->nr_actions--;
+
+	if (action->flags & IRQF_FORCE_RESUME)
+		desc->force_resume_depth--;
+
+	if (action->flags & IRQF_NO_SUSPEND)
+		desc->no_suspend_depth--;
+}
+
+static bool suspend_device_irq(struct irq_desc *desc, int irq)
+{
+	if (!desc->action || desc->no_suspend_depth)
+		return false;
+
+	if (irqd_is_wakeup_set(&desc->irq_data)) {
+		irqd_set(&desc->irq_data, IRQD_WAKEUP_ARMED);
+		/*
+		 * We return true here to force the caller to issue
+		 * synchronize_irq(). We need to make sure that the
+		 * IRQD_WAKEUP_ARMED is visible before we return from
+		 * suspend_device_irqs().
+		 */
+		return true;
+	}
+
+	desc->istate |= IRQS_SUSPENDED;
+	__disable_irq(desc, irq);
+
+	/*
+	 * Hardware which has no wakeup source configuration facility
+	 * requires that the non wakeup interrupts are masked at the
+	 * chip level. The chip implementation indicates that with
+	 * IRQCHIP_MASK_ON_SUSPEND.
+	 */
+	if (irq_desc_get_chip(desc)->flags & IRQCHIP_MASK_ON_SUSPEND)
+		mask_irq(desc);
+	return true;
+}
+
 /**
  * suspend_device_irqs - disable all currently enabled interrupt lines
  *
- * During system-wide suspend or hibernation device drivers need to be prevented
- * from receiving interrupts and this function is provided for this purpose.
- * It marks all interrupt lines in use, except for the timer ones, as disabled
- * and sets the IRQS_SUSPENDED flag for each of them.
+ * During system-wide suspend or hibernation device drivers need to be
+ * prevented from receiving interrupts and this function is provided
+ * for this purpose.
+ *
+ * So we disable all interrupts and mark them IRQS_SUSPENDED except
+ * for those which are unused, those which are marked as not
+ * suspendable via an interrupt request with the flag IRQF_NO_SUSPEND
+ * set and those which are marked as active wakeup sources.
+ *
+ * The active wakeup sources are handled by the flow handler entry
+ * code which checks for the IRQD_WAKEUP_ARMED flag, suspends the
+ * interrupt and notifies the pm core about the wakeup.
  */
 void suspend_device_irqs(void)
 {
@@ -28,18 +116,36 @@ void suspend_device_irqs(void)
 
 	for_each_irq_desc(irq, desc) {
 		unsigned long flags;
+		bool sync;
 
 		raw_spin_lock_irqsave(&desc->lock, flags);
-		__disable_irq(desc, irq, true);
+		sync = suspend_device_irq(desc, irq);
 		raw_spin_unlock_irqrestore(&desc->lock, flags);
-	}
 
-	for_each_irq_desc(irq, desc)
-		if (desc->istate & IRQS_SUSPENDED)
+		if (sync)
 			synchronize_irq(irq);
+	}
 }
 EXPORT_SYMBOL_GPL(suspend_device_irqs);
 
+static void resume_irq(struct irq_desc *desc, int irq)
+{
+	irqd_clear(&desc->irq_data, IRQD_WAKEUP_ARMED);
+
+	if (desc->istate & IRQS_SUSPENDED)
+		goto resume;
+
+	/* Force resume the interrupt? */
+	if (!desc->force_resume_depth)
+		return;
+
+	/* Pretend that it got disabled ! */
+	desc->depth++;
+resume:
+	desc->istate &= ~IRQS_SUSPENDED;
+	__enable_irq(desc, irq);
+}
+
 static void resume_irqs(bool want_early)
 {
 	struct irq_desc *desc;
@@ -54,7 +160,7 @@ static void resume_irqs(bool want_early)
 			continue;
 
 		raw_spin_lock_irqsave(&desc->lock, flags);
-		__enable_irq(desc, irq, true);
+		resume_irq(desc, irq);
 		raw_spin_unlock_irqrestore(&desc->lock, flags);
 	}
 }
@@ -93,38 +199,3 @@ void resume_device_irqs(void)
 	resume_irqs(false);
 }
 EXPORT_SYMBOL_GPL(resume_device_irqs);
-
-/**
- * check_wakeup_irqs - check if any wake-up interrupts are pending
- */
-int check_wakeup_irqs(void)
-{
-	struct irq_desc *desc;
-	int irq;
-
-	for_each_irq_desc(irq, desc) {
-		/*
-		 * Only interrupts which are marked as wakeup source
-		 * and have not been disabled before the suspend check
-		 * can abort suspend.
-		 */
-		if (irqd_is_wakeup_set(&desc->irq_data)) {
-			if (desc->depth == 1 && desc->istate & IRQS_PENDING)
-				return -EBUSY;
-			continue;
-		}
-		/*
-		 * Check the non wakeup interrupts whether they need
-		 * to be masked before finally going into suspend
-		 * state. That's for hardware which has no wakeup
-		 * source configuration facility. The chip
-		 * implementation indicates that with
-		 * IRQCHIP_MASK_ON_SUSPEND.
-		 */
-		if (desc->istate & IRQS_SUSPENDED &&
-		    irq_desc_get_chip(desc)->flags & IRQCHIP_MASK_ON_SUSPEND)
-			mask_irq(desc);
-	}
-
-	return 0;
-}

kernel/power/process.c

@@ -129,6 +129,7 @@ int freeze_processes(void)
 	if (!pm_freezing)
 		atomic_inc(&system_freezing_cnt);
 
+	pm_wakeup_clear();
 	printk("Freezing user space processes ... ");
 	pm_freezing = true;
 	error = try_to_freeze_tasks(true);