diff options
| author | Ondrej Zary <linux@rainbow-software.org> | 2012-12-11 22:18:05 +0100 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2013-01-03 03:33:36 +0000 |
| commit | 6f2aad2b4120b1770d8bc89c5b6feef347238585 (patch) | |
| tree | ad76cf4e83f106cfd894c089de9ff68ca2e84999 | |
| parent | 56201be51f36f6e633872c0686016749c15853a0 (diff) | |
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: Ben Hutchings <ben@decadent.org.uk>
| -rw-r--r-- | drivers/input/serio/i8042-x86ia64io.h | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/drivers/input/serio/i8042-x86ia64io.h b/drivers/input/serio/i8042-x86ia64io.h index cd1a843adb69..031270c9f9ff 100644 --- a/drivers/input/serio/i8042-x86ia64io.h +++ b/drivers/input/serio/i8042-x86ia64io.h @@ -914,6 +914,7 @@ 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; @@ -953,6 +954,14 @@ 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; |