linux-kernel - [tip:x86/urgent] x86, 8042: Enable A20 using KBC to fix S3 resume on some MSI laptops

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Date:	Wed, 12 Dec 2012 13:52:47 -0800
From:	tip-bot for Ondrej Zary <linux@...nbow-software.org>
To:	linux-tip-commits@...r.kernel.org
Cc:	linux-kernel@...r.kernel.org, linux@...nbow-software.org,
	hpa@...or.com, mingo@...nel.org, stable@...r.kernel.org,
	alan@...rguk.ukuu.org.uk, dmitry.torokhov@...il.com,
	tglx@...utronix.de, hpa@...ux.intel.com, rjw@...k.pl
Subject: [tip:x86/urgent] x86, 8042:
  Enable A20 using KBC to fix S3 resume on some MSI laptops

Commit-ID:  ad68652412276f68ad4fe3e1ecf5ee6880876783
Gitweb:     http://git.kernel.org/tip/ad68652412276f68ad4fe3e1ecf5ee6880876783
Author:     Ondrej Zary <linux@...nbow-software.org>
AuthorDate: Tue, 11 Dec 2012 22:18:05 +0100
Committer:  H. Peter Anvin <hpa@...ux.intel.com>
CommitDate: Tue, 11 Dec 2012 14:55:16 -0800

x86, 8042: Enable A20 using KBC to fix S3 resume on some MSI laptops

Some MSI laptop BIOSes are broken - INT 15h code uses port 92h to enable A20
line but resume code assumes that KBC was used.
The laptop will not resume from S3 otherwise but powers off after a while
and then powers on again stuck with a blank screen.

Fix it by enabling A20 using KBC in i8042_platform_init for x86.

Fixes https://bugzilla.kernel.org/show_bug.cgi?id=12878

Signed-off-by: Ondrej Zary <linux@...nbow-software.org>
Cc: Dmitry Torokhov <dmitry.torokhov@...il.com>
Cc: Alan Cox <alan@...rguk.ukuu.org.uk>
Cc: Rafael J. Wysocki <rjw@...k.pl>
Cc: <stable@...r.kernel.org>
Link: http://lkml.kernel.org/r/201212112218.06551.linux@rainbow-software.org
Signed-off-by: H. Peter Anvin <hpa@...ux.intel.com>
---
 drivers/input/serio/i8042-x86ia64io.h | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/input/serio/i8042-x86ia64io.h b/drivers/input/serio/i8042-x86ia64io.h
index d6cc77a..5f306f7 100644
--- a/drivers/input/serio/i8042-x86ia64io.h
+++ b/drivers/input/serio/i8042-x86ia64io.h
@@ -921,6 +921,7 @@ static int __init i8042_platform_init(void)
 	int retval;
 
 #ifdef CONFIG_X86
+	u8 a20_on = 0xdf;
 	/* Just return if pre-detection shows no i8042 controller exist */
 	if (!x86_platform.i8042_detect())
 		return -ENODEV;
@@ -960,6 +961,14 @@ static int __init i8042_platform_init(void)
 
 	if (dmi_check_system(i8042_dmi_dritek_table))
 		i8042_dritek = true;
+
+	/*
+	 * A20 was already enabled during early kernel init. But some buggy
+	 * BIOSes (in MSI Laptops) require A20 to be enabled using 8042 to
+	 * resume from S3. So we do it here and hope that nothing breaks.
+	 */
+	i8042_command(&a20_on, 0x10d1);
+	i8042_command(NULL, 0x00ff);	/* Null command for SMM firmware */
 #endif /* CONFIG_X86 */
 
 	return retval;
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/