From: Alan Stern <stern@rowland.harvard.edu>
Date: Fri, 29 Feb 2008 16:50:22 +0000 (-0500)
Subject: PM: fix new mutex-locking bug in the PM core
X-Git-Tag: firefly_0821_release~22103^2~3
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=1b3cbec1dcb6747b587b40335f5de1d9e035063c;p=firefly-linux-kernel-4.4.55.git

PM: fix new mutex-locking bug in the PM core

This patch (as1041) fixes a bug introduced by the
acquire-all-device-semaphores reversion.  The error pathway of
dpm_suspend() fails to reacquire a mutex it should be holding.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---

diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c
index b0c16f6fc186..d887d5cb5bef 100644
--- a/drivers/base/power/main.c
+++ b/drivers/base/power/main.c
@@ -428,6 +428,7 @@ static int dpm_suspend(pm_message_t state)
 
 		mutex_unlock(&dpm_list_mtx);
 		error = suspend_device(dev, state);
+		mutex_lock(&dpm_list_mtx);
 		if (error) {
 			printk(KERN_ERR "Could not suspend device %s: "
 					"error %d%s\n",
@@ -438,7 +439,6 @@ static int dpm_suspend(pm_message_t state)
 					""));
 			break;
 		}
-		mutex_lock(&dpm_list_mtx);
 		if (!list_empty(&dev->power.entry))
 			list_move(&dev->power.entry, &dpm_off);
 	}