Merge back earlier 'pm-sleep' material for v4.4.

Documentation/ABI/testing/sysfs-power

···
 		Writing a "1" enables this printing while writing a "0"
 		disables it.  The default value is "0".  Reading from this file
 		will display the current value.
+
+What:		/sys/power/pm_wakeup_irq
+Date:		April 2015
+Contact:	Alexandra Yates <[e-mail]>
+Description:
+		The /sys/power/pm_wakeup_irq file reports to user space the IRQ
+		number of the first wakeup interrupt (that is, the first
+		interrupt from an IRQ line armed for system wakeup) seen by the
+		kernel during the most recent system suspend/resume cycle.
+
+		This output is useful for system wakeup diagnostics of spurious
+		wakeup interrupts.

drivers/base/power/wakeup.c

···
  */
 bool events_check_enabled __read_mostly;
 
+/* First wakeup IRQ seen by the kernel in the last cycle. */
+unsigned int pm_wakeup_irq __read_mostly;
+
 /* If set and the system is suspending, terminate the suspend. */
 static bool pm_abort_suspend __read_mostly;
 
···
 	if (!ws)
 		return NULL;
 
-	wakeup_source_prepare(ws, name ? kstrdup(name, GFP_KERNEL) : NULL);
+	wakeup_source_prepare(ws, name ? kstrdup_const(name, GFP_KERNEL) : NULL);
 	return ws;
 }
 EXPORT_SYMBOL_GPL(wakeup_source_create);
···
 
 	wakeup_source_drop(ws);
 	wakeup_source_record(ws);
-	kfree(ws->name);
+	kfree_const(ws->name);
 	kfree(ws);
 }
 EXPORT_SYMBOL_GPL(wakeup_source_destroy);
···
 void pm_wakeup_clear(void)
 {
 	pm_abort_suspend = false;
+	pm_wakeup_irq = 0;
+}
+
+void pm_system_irq_wakeup(unsigned int irq_number)
+{
+	if (pm_wakeup_irq == 0) {
+		pm_wakeup_irq = irq_number;
+		pm_system_wakeup();
+	}
 }
 
 /**

include/linux/suspend.h

···
 
 /* drivers/base/power/wakeup.c */
 extern bool events_check_enabled;
+extern unsigned int pm_wakeup_irq;
 
 extern bool pm_wakeup_pending(void);
 extern void pm_system_wakeup(void);
 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);
 extern void pm_wakep_autosleep_enabled(bool set);
···
 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 pm_system_irq_wakeup(unsigned int irq_number) {}
 
 static inline void lock_system_sleep(void) {}
 static inline void unlock_system_sleep(void) {}

kernel/irq/pm.c

···
 		desc->istate |= IRQS_SUSPENDED | IRQS_PENDING;
 		desc->depth++;
 		irq_disable(desc);
-		pm_system_wakeup();
+		pm_system_irq_wakeup(irq_desc_get_irq(desc));
 		return true;
 	}
 	return false;

kernel/power/main.c

···
 {
 	pm_print_times_enabled = !!initcall_debug;
 }
+
+static ssize_t pm_wakeup_irq_show(struct kobject *kobj,
+					struct kobj_attribute *attr,
+					char *buf)
+{
+	return pm_wakeup_irq ? sprintf(buf, "%u\n", pm_wakeup_irq) : -ENODATA;
+}
+
+static ssize_t pm_wakeup_irq_store(struct kobject *kobj,
+					struct kobj_attribute *attr,
+					const char *buf, size_t n)
+{
+	return -EINVAL;
+}
+power_attr(pm_wakeup_irq);
+
 #else /* !CONFIG_PM_SLEEP_DEBUG */
 static inline void pm_print_times_init(void) {}
 #endif /* CONFIG_PM_SLEEP_DEBUG */
···
 #endif
 #ifdef CONFIG_PM_SLEEP_DEBUG
 	&pm_print_times_attr.attr,
+	&pm_wakeup_irq_attr.attr,
 #endif
 #endif
 #ifdef CONFIG_FREEZER