PM: hibernate: Add more logging on hibernation failure

Hibernation fails when the kernel cannot allocate enough memory
to copy all pages of RAM in use.

Ensure that the failure reason is clearly logged, and clearly
attributable to the hibernation module.

Signed-off-by: Luigi Semenzato <semenzato@google.com>
[ rjw: Subject & changelog ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 12 insertions, 11 deletions

diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c
index 3c0a5a8170b0..6dbeedb7354c 100644
--- a/kernel/power/hibernate.c
+++ b/kernel/power/hibernate.c
@@ -9,7 +9,7 @@
  * Copyright (C) 2012 Bojan Smojver <bojan@rexursive.com>
  */
 
-#define pr_fmt(fmt) "PM: " fmt
+#define pr_fmt(fmt) "PM: hibernation: " fmt
 
 #include <linux/export.h>
 #include <linux/suspend.h>
@@ -106,7 +106,7 @@ EXPORT_SYMBOL(system_entering_hibernation);
 #ifdef CONFIG_PM_DEBUG
 static void hibernation_debug_sleep(void)
 {
-	pr_info("hibernation debug: Waiting for 5 seconds.\n");
+	pr_info("debug: Waiting for 5 seconds.\n");
 	mdelay(5000);
 }
 
@@ -277,7 +277,7 @@ static int create_image(int platform_mode)
 
 	error = dpm_suspend_end(PMSG_FREEZE);
 	if (error) {
-		pr_err("Some devices failed to power down, aborting hibernation\n");
+		pr_err("Some devices failed to power down, aborting\n");
 		return error;
 	}
 
@@ -295,7 +295,7 @@ static int create_image(int platform_mode)
 
 	error = syscore_suspend();
 	if (error) {
-		pr_err("Some system devices failed to power down, aborting hibernation\n");
+		pr_err("Some system devices failed to power down, aborting\n");
 		goto Enable_irqs;
 	}
 
@@ -310,7 +310,7 @@ static int create_image(int platform_mode)
 	restore_processor_state();
 	trace_suspend_resume(TPS("machine_suspend"), PM_EVENT_HIBERNATE, false);
 	if (error)
-		pr_err("Error %d creating hibernation image\n", error);
+		pr_err("Error %d creating image\n", error);
 
 	if (!in_suspend) {
 		events_check_enabled = false;
@@ -680,7 +680,7 @@ static int load_image_and_restore(void)
 	if (!error)
 		hibernation_restore(flags & SF_PLATFORM_MODE);
 
-	pr_err("Failed to load hibernation image, recovering.\n");
+	pr_err("Failed to load image, recovering.\n");
 	swsusp_free();
 	free_basic_memory_bitmaps();
  Unlock:
@@ -743,7 +743,7 @@ int hibernate(void)
 		else
 		        flags |= SF_CRC32_MODE;
 
-		pm_pr_dbg("Writing image.\n");
+		pm_pr_dbg("Writing hibernation image.\n");
 		error = swsusp_write(flags);
 		swsusp_free();
 		if (!error) {
@@ -755,7 +755,7 @@ int hibernate(void)
 		in_suspend = 0;
 		pm_restore_gfp_mask();
 	} else {
-		pm_pr_dbg("Image restored successfully.\n");
+		pm_pr_dbg("Hibernation image restored successfully.\n");
 	}
 
  Free_bitmaps:
@@ -894,7 +894,7 @@ static int software_resume(void)
 		goto Close_Finish;
 	}
 
-	pm_pr_dbg("Preparing processes for restore.\n");
+	pm_pr_dbg("Preparing processes for hibernation restore.\n");
 	error = freeze_processes();
 	if (error)
 		goto Close_Finish;
@@ -903,7 +903,7 @@ static int software_resume(void)
  Finish:
 	__pm_notifier_call_chain(PM_POST_RESTORE, nr_calls, NULL);
 	pm_restore_console();
-	pr_info("resume from hibernation failed (%d)\n", error);
+	pr_info("resume failed (%d)\n", error);
 	atomic_inc(&snapshot_device_available);
 	/* For success case, the suspend path will release the lock */
  Unlock:
@@ -1068,7 +1068,8 @@ static ssize_t resume_store(struct kobject *kobj, struct kobj_attribute *attr,
 	lock_system_sleep();
 	swsusp_resume_device = res;
 	unlock_system_sleep();
-	pm_pr_dbg("Configured resume from disk to %u\n", swsusp_resume_device);
+	pm_pr_dbg("Configured hibernation resume from disk to %u\n",
+		  swsusp_resume_device);
 	noresume = 0;
 	software_resume();
 	return n;