PM / Hibernate: Use get_gendisk to verify partition if resume_file is integer format

Sometimes resume= parameter comes in integer style (e.g. major:minor)
and then name_to_dev_t can not detect partition properly. (especially
async device like usb, mmc).

This patch calls get_gendisk() if resumewait is true and resume_file
is in integer format to work around this problem.

Signed-off-by: Minho Ban <mhban@samsung.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

2 files changed, 15 insertions, 0 deletions

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index c1601e5a8b7..5900b49323c 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -2372,6 +2372,8 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
 
         resume=         [SWSUSP]
                         Specify the partition device for software suspend
+                        Format:
+                        {/dev/<dev> | PARTUUID=<uuid> | <int>:<int> | <hex>}
 
         resume_offset=  [SWSUSP]
                         Specify the offset from the beginning of the partition
diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c
index e09dfbfeece..8b53db38a27 100644
--- a/kernel/power/hibernate.c
+++ b/kernel/power/hibernate.c
@@ -25,6 +25,8 @@
 #include <linux/freezer.h>
 #include <linux/gfp.h>
 #include <linux/syscore_ops.h>
+#include <linux/ctype.h>
+#include <linux/genhd.h>
 #include <scsi/scsi_scan.h>
 
 #include "power.h"
@@ -722,6 +724,17 @@ static int software_resume(void)
 
         /* Check if the device is there */
         swsusp_resume_device = name_to_dev_t(resume_file);
+
+        /*
+         * name_to_dev_t is ineffective to verify parition if resume_file is in
+         * integer format. (e.g. major:minor)
+         */
+        if (isdigit(resume_file[0]) && resume_wait) {
+                int partno;
+                while (!get_gendisk(swsusp_resume_device, &partno))
+                        msleep(10);
+        }
+
         if (!swsusp_resume_device) {
                 /*
                  * Some device discovery might still be in progress; we need