Re: [PATCH v3] Enable A20 using KBC for some MSI laptops to fix S3 resume
From: Ondrej Zary <hidden>
Date: 2012-12-11 20:30:01
Also in:
lkml
Subsystem:
input (keyboard, mouse, joystick, touchscreen) drivers, the rest · Maintainers:
Dmitry Torokhov, Linus Torvalds
On Tuesday 11 December 2012 20:07:50 H. Peter Anvin wrote:
On 12/11/2012 10:59 AM, Ondrej Zary wrote:quoted
As I said before, the BIOS probably breaks on resume before any Linux code is executed. So any fix must be done before suspending.Well, that code should be independent of A20, being in low memory, but if the BIOS itself crashes, then that's... yeah.quoted
I hate quirks too. A general solution would be to always enable A20 using KBC (if KBC is present) but that's probably not acceptable.I don't see why not. If so we could just do it as part of the initialization of the i8042 driver.
Something like this? (It works.)
diff --git a/drivers/input/serio/i8042-x86ia64io.h b/drivers/input/serio/i8042-x86ia64io.h
index d6cc77a..0807ac7 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 +961,13 @@ 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); #endif /* CONFIG_X86 */ return retval;
--
Ondrej Zary