SRU - LP41091 - Crash when connecting to port replicator

[Steve Conklin]

>From b0e0c2ea951dffb31b99fab160fc674d05c95f99 Mon Sep 17 00:00:00 2001
From: Shaohua Li <shaohua.li at intel.com>
Date: Thu, 28 Aug 2008 10:02:03 +0800
Subject: [PATCH] UBUNTU: Ubuntu crash when connecting to port replicator
OriginalAuthor:    Shaohua Li <shaohua.li at intel.com>

Bug: #41091
cherry picked from upstream.
Confirmed by a community member to solve the problem.

ACPI: dock: avoid check _STA method

In some BIOSes, every _STA method call will send a notification again,
this cause freeze. And in some BIOSes, it appears _STA should be called
after _DCK. This tries to avoid calls _STA, and still keep the device
present check.

http://bugzilla.kernel.org/show_bug.cgi?id=10431

Signed-off-by: Shaohua Li <shaohua.li at intel.com>
Signed-off-by: Len Brown <len.brown at intel.com>
Signed-off-by: Steve Conklin <sconklin at canonical.com>
---
 drivers/acpi/dock.c |    5 ++++-
 1 files changed, 4 insertions(+), 1 deletions(-)

diff --git a/drivers/acpi/dock.c b/drivers/acpi/dock.c
index 7d2edf1..25d2161 100644
--- a/drivers/acpi/dock.c
+++ b/drivers/acpi/dock.c
@@ -604,14 +604,17 @@ static int handle_eject_request(struct dock_station *ds, u32 event)
 static void dock_notify(acpi_handle handle, u32 event, void *data)
 {
 	struct dock_station *ds = data;
+	struct acpi_device *tmp;
 
 	switch (event) {
 	case ACPI_NOTIFY_BUS_CHECK:
-		if (!dock_in_progress(ds) && dock_present(ds)) {
+		if (!dock_in_progress(ds) && acpi_bus_get_device(ds->handle,
+		   &tmp)) {
 			begin_dock(ds);
 			dock(ds);
 			if (!dock_present(ds)) {
 				printk(KERN_ERR PREFIX "Unable to dock!\n");
+				complete_dock(ds);
 				break;
 			}
 			atomic_notifier_call_chain(&dock_notifier_list,
-- 
1.5.6.3