PM/resume: wait for device probing to finish

the resume code does not currently wait for device probing to finish.
Even without async function calls this is dicey and not correct,
but with async function calls during the boot sequence this is going
to get hit more...

This patch adds the synchronization using the newly introduced helper.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Len Brown <lenb@kernel.org>
Acked-by: Greg KH <gregkh@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kernel/power/disk.c

@@ -594,6 +594,12 @@ static int software_resume(void)
 	int error;
 	unsigned int flags;
 
+	/*
+	 * If the user said "noresume".. bail out early.
+	 */
+	if (noresume)
+		return 0;
+
 	/*
 	 * name_to_dev_t() below takes a sysfs buffer mutex when sysfs
 	 * is configured into the kernel. Since the regular hibernate
@@ -610,6 +616,11 @@ static int software_resume(void)
 			mutex_unlock(&pm_mutex);
 			return -ENOENT;
 		}
+		/*
+		 * Some device discovery might still be in progress; we need
+		 * to wait for this to finish.
+		 */
+		wait_for_device_probe();
 		swsusp_resume_device = name_to_dev_t(resume_file);
 		pr_debug("PM: Resume from partition %s\n", resume_file);
 	} else {