From 276c234515c9491d591c0463c118d1f497d726f3 Mon Sep 17 00:00:00 2001 From: Ondrej Zary <linux@rainbow-software.org> Date: Tue, 11 Dec 2012 22:18:05 +0100 Subject: [PATCH] x86, 8042: Enable A20 using KBC to fix S3 resume on some MSI laptops commit ad68652412276f68ad4fe3e1ecf5ee6880876783 upstream. 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@rainbow-software.org> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Rafael J. Wysocki <rjw@sisk.pl> Link: http://lkml.kernel.org/r/201212112218.06551.linux@rainbow-software.org Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- 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 e01fd4cc298c..20153fe81512 100644 --- a/drivers/input/serio/i8042-x86ia64io.h +++ b/drivers/input/serio/i8042-x86ia64io.h @@ -900,6 +900,7 @@ 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; @@ -939,6 +940,14 @@ 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; -- 2.34.1