From 33a2285d96b5e7b9500612ec623bf4313397bb53 Mon Sep 17 00:00:00 2001
From: Lin Ming <ming.m.lin@intel.com>
Date: Fri, 6 Jul 2012 12:06:57 +0800
Subject: [SCSI] scsi_pm: set device runtime state before parent suspended

There is a race in scsi_bus_resume_common when set device's runtime
state to active after pm_runtime_put_sync(dev->parent).

Parent device may have been suspended so pm_runtime_set_active(dev) will
fail with -EBUSY.

Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
---
 drivers/scsi/scsi_pm.c | 23 ++++++++++++-----------
 1 file changed, 12 insertions(+), 11 deletions(-)

(limited to 'drivers/scsi')

diff --git a/drivers/scsi/scsi_pm.c b/drivers/scsi/scsi_pm.c
index d4201ded3b22..dc0ad85853e2 100644
--- a/drivers/scsi/scsi_pm.c
+++ b/drivers/scsi/scsi_pm.c
@@ -76,23 +76,24 @@ static int scsi_bus_resume_common(struct device *dev)
 {
 	int err = 0;
 
-	if (scsi_is_sdev_device(dev)) {
-		/*
-		 * Parent device may have runtime suspended as soon as
-		 * it is woken up during the system resume.
-		 *
-		 * Resume it on behalf of child.
-		 */
-		pm_runtime_get_sync(dev->parent);
-		err = scsi_dev_type_resume(dev);
-		pm_runtime_put_sync(dev->parent);
-	}
+	/*
+	 * Parent device may have runtime suspended as soon as
+	 * it is woken up during the system resume.
+	 *
+	 * Resume it on behalf of child.
+	 */
+	pm_runtime_get_sync(dev->parent);
 
+	if (scsi_is_sdev_device(dev))
+		err = scsi_dev_type_resume(dev);
 	if (err == 0) {
 		pm_runtime_disable(dev);
 		pm_runtime_set_active(dev);
 		pm_runtime_enable(dev);
 	}
+
+	pm_runtime_put_sync(dev->parent);
+
 	return err;
 }
 
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