Oneiric SRU: Phantom battery appears after resume from suspend

[Tim Gardner]

>From 67d3ca0df4bf7cb82d8459417e0b99090bbc0c92 Mon Sep 17 00:00:00 2001
From: Lan Tianyu <tianyu.lan at intel.com>
Date: Thu, 30 Jun 2011 11:33:58 +0800
Subject: [PATCH] ACPI / Battery: Add the check before refresh sysfs in the battery_notify()

BugLink: http://bugs.launchpad.net/bugs/852406

In the commit 25be5821, add the refresh sysfs when system resumes
from suspending. But it didn't check that the battery exists. This
will cause battery sysfs files added when the battery doesn't exist.
This patch add the check before refreshing.

	https://bugzilla.kernel.org/show_bug.cgi?id=35642

Signed-off-by: Lan Tianyu <tianyu.lan at intel.com>
Signed-off-by: Len Brown <len.brown at intel.com>
(cherry picked from commit 6e17fb6aa1a67afa1827ae317c3594040f055730)

Signed-off-by: Tim Gardner <tim.gardner at canonical.com>
---
 drivers/acpi/battery.c |    6 ++++--
 1 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/acpi/battery.c b/drivers/acpi/battery.c
index 929f5e8..1cf8434 100644
--- a/drivers/acpi/battery.c
+++ b/drivers/acpi/battery.c
@@ -949,8 +949,10 @@ static int battery_notify(struct notifier_block *nb,
 						    pm_nb);
 	switch (mode) {
 	case PM_POST_SUSPEND:
-		sysfs_remove_battery(battery);
-		sysfs_add_battery(battery);
+		if (battery->bat.dev) {
+			sysfs_remove_battery(battery);
+			sysfs_add_battery(battery);
+		}
 		break;
 	}
 
-- 
1.7.0.4