kernel/disable-i8042-check-on-apple-mac.patch

Bugzilla: N/A
Upstream-status: http://lkml.indiana.edu/hypermail/linux/kernel/1005.0/00938.html (and pinged on Dec 17, 2013)

From 2a79554c864ac58fa2ad982f0fcee2cc2aa33eb5 Mon Sep 17 00:00:00 2001
From: Bastien Nocera <hadess@hadess.net>
Date: Thu, 20 May 2010 10:30:31 -0400
Subject: Disable i8042 checks on Intel Apple Macs

As those computers never had any i8042 controllers, and the
current lookup code could potentially lock up/hang/wait for
timeout for long periods of time.

Fixes intermittent hangs on boot on a MacbookAir1,1

Signed-off-by: Bastien Nocera <hadess@hadess.net>
---
 drivers/input/serio/i8042.c |   22 ++++++++++++++++++++++
 1 files changed, 22 insertions(+), 0 deletions(-)

diff --git a/drivers/input/serio/i8042.c b/drivers/input/serio/i8042.c
index 6440a8f..4d7cf98 100644
--- a/drivers/input/serio/i8042.c
+++ b/drivers/input/serio/i8042.c
@@ -1451,6 +1451,22 @@ static struct platform_driver i8042_driver = {
 	.shutdown	= i8042_shutdown,
 };
 
+#ifdef CONFIG_DMI
+static struct dmi_system_id __initdata dmi_system_table[] = {
+	{
+		.matches = {
+			DMI_MATCH(DMI_BIOS_VENDOR, "Apple Computer, Inc.")
+		},
+	},
+	{
+		.matches = {
+			DMI_MATCH(DMI_BIOS_VENDOR, "Apple Inc.")
+		},
+	},
+	{}
+};
+#endif /*CONFIG_DMI*/
+
 static int __init i8042_init(void)
 {
 	struct platform_device *pdev;
@@ -1458,6 +1474,12 @@ static int __init i8042_init(void)
 
 	dbg_init();
 
+#ifdef CONFIG_DMI
+	/* Intel Apple Macs never have an i8042 controller */
+	if (dmi_check_system(dmi_system_table) > 0)
+		return -ENODEV;
+#endif /*CONFIG_DMI*/
+
 	err = i8042_platform_init();
 	if (err)
 		return err;
-- 
1.7.0.1