power: Adds functionality to log the last suspend abort reason.

Extends the last_resume_reason to log suspend abort reason. The abort
reasons will have "Abort:" appended at the start to distinguish itself
from the resume reason.

Signed-off-by: Ruchi Kandoi <kandoiruchi@google.com>
Change-Id: I3207f1844e3d87c706dfc298fb10e1c648814c5f

kernel/power/process.c

@@ -18,6 +18,7 @@
 #include <linux/workqueue.h>
 #include <linux/kmod.h>
 #include <trace/events/power.h>
+#include <linux/wakeup_reason.h>
 
 /* 
  * Timeout for stopping processes
@@ -35,6 +36,7 @@ static int try_to_freeze_tasks(bool user_only)
 	unsigned int elapsed_msecs;
 	bool wakeup = false;
 	int sleep_usecs = USEC_PER_MSEC;
+	char suspend_abort[MAX_SUSPEND_ABORT_LEN];
 
 	do_gettimeofday(&start);
 
@@ -64,6 +66,9 @@ static int try_to_freeze_tasks(bool user_only)
 			break;
 
 		if (pm_wakeup_pending()) {
+			pm_get_active_wakeup_sources(suspend_abort,
+				MAX_SUSPEND_ABORT_LEN);
+			log_suspend_abort_reason(suspend_abort);
 			wakeup = true;
 			break;
 		}

kernel/power/suspend.c

@@ -30,6 +30,7 @@
 #include <trace/events/power.h>
 #include <linux/compiler.h>
 #include <linux/moduleparam.h>
+#include <linux/wakeup_reason.h>
 
 #include "power.h"
 
@@ -313,7 +314,8 @@ void __weak arch_suspend_enable_irqs(void)
  */
 static int suspend_enter(suspend_state_t state, bool *wakeup)
 {
-	int error;
+	char suspend_abort[MAX_SUSPEND_ABORT_LEN];
+	int error, last_dev;
 
 	error = platform_suspend_prepare(state);
 	if (error)
@@ -321,7 +323,11 @@ static int suspend_enter(suspend_state_t state, bool *wakeup)
 
 	error = dpm_suspend_late(PMSG_SUSPEND);
 	if (error) {
+		last_dev = suspend_stats.last_failed_dev + REC_FAILED_NUM - 1;
+		last_dev %= REC_FAILED_NUM;
 		printk(KERN_ERR "PM: late suspend of devices failed\n");
+		log_suspend_abort_reason("%s device failed to power down",
+			suspend_stats.failed_devs[last_dev]);
 		goto Platform_finish;
 	}
 	error = platform_suspend_prepare_late(state);
@@ -330,7 +336,11 @@ static int suspend_enter(suspend_state_t state, bool *wakeup)
 
 	error = dpm_suspend_noirq(PMSG_SUSPEND);
 	if (error) {
+		last_dev = suspend_stats.last_failed_dev + REC_FAILED_NUM - 1;
+		last_dev %= REC_FAILED_NUM;
 		printk(KERN_ERR "PM: noirq suspend of devices failed\n");
+		log_suspend_abort_reason("noirq suspend of %s device failed",
+			suspend_stats.failed_devs[last_dev]);
 		goto Platform_early_resume;
 	}
 	error = platform_suspend_prepare_noirq(state);
@@ -354,8 +364,10 @@ static int suspend_enter(suspend_state_t state, bool *wakeup)
 	}
 
 	error = disable_nonboot_cpus();
-	if (error || suspend_test(TEST_CPUS))
+	if (error || suspend_test(TEST_CPUS)) {
+		log_suspend_abort_reason("Disabling non-boot cpus failed");
 		goto Enable_cpus;
+	}
 
 	arch_suspend_disable_irqs();
 	BUG_ON(!irqs_disabled());
@@ -371,6 +383,9 @@ static int suspend_enter(suspend_state_t state, bool *wakeup)
 				state, false);
 			events_check_enabled = false;
 		} else if (*wakeup) {
+			pm_get_active_wakeup_sources(suspend_abort,
+				MAX_SUSPEND_ABORT_LEN);
+			log_suspend_abort_reason(suspend_abort);
 			error = -EBUSY;
 		}
 		syscore_resume();
@@ -418,6 +433,7 @@ int suspend_devices_and_enter(suspend_state_t state)
 	error = dpm_suspend_start(PMSG_SUSPEND);
 	if (error) {
 		pr_err("PM: Some devices failed to suspend, or early wake event detected\n");
+		log_suspend_abort_reason("Some devices failed to suspend, or early wake event detected");
 		goto Recover_platform;
 	}
 	suspend_test_finish("suspend devices");

kernel/power/wakeup_reason.c

@@ -31,6 +31,8 @@
 #define MAX_WAKEUP_REASON_IRQS 32
 static int irq_list[MAX_WAKEUP_REASON_IRQS];
 static int irqcount;
+static bool suspend_abort;
+static char abort_reason[MAX_SUSPEND_ABORT_LEN];
 static struct kobject *wakeup_reason;
 static spinlock_t resume_reason_lock;
 
@@ -40,14 +42,18 @@ static ssize_t last_resume_reason_show(struct kobject *kobj, struct kobj_attribu
 	int irq_no, buf_offset = 0;
 	struct irq_desc *desc;
 	spin_lock(&resume_reason_lock);
-	for (irq_no = 0; irq_no < irqcount; irq_no++) {
-		desc = irq_to_desc(irq_list[irq_no]);
-		if (desc && desc->action && desc->action->name)
-			buf_offset += sprintf(buf + buf_offset, "%d %s\n",
-					irq_list[irq_no], desc->action->name);
-		else
-			buf_offset += sprintf(buf + buf_offset, "%d\n",
-					irq_list[irq_no]);
+	if (suspend_abort) {
+		buf_offset = sprintf(buf, "Abort: %s", abort_reason);
+	} else {
+		for (irq_no = 0; irq_no < irqcount; irq_no++) {
+			desc = irq_to_desc(irq_list[irq_no]);
+			if (desc && desc->action && desc->action->name)
+				buf_offset += sprintf(buf + buf_offset, "%d %s\n",
+						irq_list[irq_no], desc->action->name);
+			else
+				buf_offset += sprintf(buf + buf_offset, "%d\n",
+						irq_list[irq_no]);
+		}
 	}
 	spin_unlock(&resume_reason_lock);
 	return buf_offset;
@@ -89,6 +95,25 @@ void log_wakeup_reason(int irq)
 	spin_unlock(&resume_reason_lock);
 }
 
+void log_suspend_abort_reason(const char *fmt, ...)
+{
+	va_list args;
+
+	spin_lock(&resume_reason_lock);
+
+	//Suspend abort reason has already been logged.
+	if (suspend_abort) {
+		spin_unlock(&resume_reason_lock);
+		return;
+	}
+
+	suspend_abort = true;
+	va_start(args, fmt);
+	snprintf(abort_reason, MAX_SUSPEND_ABORT_LEN, fmt, args);
+	va_end(args);
+	spin_unlock(&resume_reason_lock);
+}
+
 /* Detects a suspend and clears all the previous wake up reasons*/
 static int wakeup_reason_pm_event(struct notifier_block *notifier,
 		unsigned long pm_event, void *unused)
@@ -97,6 +122,7 @@ static int wakeup_reason_pm_event(struct notifier_block *notifier,
 	case PM_SUSPEND_PREPARE:
 		spin_lock(&resume_reason_lock);
 		irqcount = 0;
+		suspend_abort = false;
 		spin_unlock(&resume_reason_lock);
 		break;
 	default: