Re: [PATCH v3] Enable A20 using KBC for some MSI laptops to fix S3 resume
From: "H. Peter Anvin" <hpa@zytor.com>
Date: 2012-12-11 20:37:15
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On 12/11/2012 12:29 PM, Ondrej Zary wrote:
Something like this? (It works.)
Something like that. We need to make sure we send the proper sequence, though, or it might break some SMM firmware...
quoted hunk ↗ jump to hunk
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;