Re: [PATCH] Enable A20 using KBC for some MSI laptops to fix S3 resume

From: H. Peter Anvin
Date: Wed Oct 24 2012 - 15:38:32 EST


Minor concern: it should do the wait for ready before sending each command.

"Rafael J. Wysocki" <rjw@xxxxxxx> wrote:

>On Wednesday 24 of October 2012 08:47:52 Ondrej Zary wrote:
>> 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. Affected laptop list and DMI data
>are from
>> bug reports at Ubuntu Launchpad.
>>
>> Tested with EX600 and PR200.
>>
>> Fixes https://bugzilla.kernel.org/show_bug.cgi?id=12878
>>
>> Signed-off-by: Ondrej Zary <linux@xxxxxxxxxxxxxxxxxxxx>
>
>Acked-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
>
>
>> --- a/arch/x86/kernel/acpi/boot.c
>> +++ b/arch/x86/kernel/acpi/boot.c
>> @@ -1349,6 +1349,20 @@ static int __init
>dmi_ignore_irq0_timer_override(const struct dmi_system_id *d)
>> }
>>
>> /*
>> + * Enable A20 line using KBC even if it's already enabled using
>other method.
>> + * This is needed for some MSI laptops to resume from S3.
>> + */
>> +static int __init a20_enable_kbc(const struct dmi_system_id *d)
>> +{
>> + printk(KERN_NOTICE "%s detected: enabling A20 using KBC\n",
>d->ident);
>> + outb(0xd1, 0x64); /* Command write */
>> + outb(0xdf, 0x60); /* A20 on */
>> + outb(0xff, 0x64); /* Null command, but UHCI wants it */
>> +
>> + return 0;
>> +}
>> +
>> +/*
>> * If your system is blacklisted here, but you find that acpi=force
>> * works for you, please contact linux-acpi@xxxxxxxxxxxxxxx
>> */
>> @@ -1423,6 +1437,60 @@ static struct dmi_system_id __initdata
>acpi_dmi_table[] = {
>> DMI_MATCH(DMI_PRODUCT_NAME, "TravelMate 360"),
>> },
>> },
>> + /*
>> + * 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.
>> + */
>> + {
>> + .callback = a20_enable_kbc,
>> + .ident = "MSI EX600 Laptop",
>> + .matches = {
>> + DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star International"),
>> + DMI_MATCH(DMI_PRODUCT_NAME, "MSI Notebook EX600"),
>> + },
>> + },
>> + {
>> + .callback = a20_enable_kbc,
>> + .ident = "MSI EX700 Laptop",
>> + .matches = {
>> + DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star International"),
>> + DMI_MATCH(DMI_PRODUCT_NAME, "EX700"),
>> + },
>> + },
>> + {
>> + .callback = a20_enable_kbc,
>> + .ident = "MSI GX700 Laptop",
>> + .matches = {
>> + DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star International"),
>> + DMI_MATCH(DMI_PRODUCT_NAME, "GX700"),
>> + },
>> + },
>> + {
>> + .callback = a20_enable_kbc,
>> + .ident = "MSI VR201 Laptop",
>> + .matches = {
>> + DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star International"),
>> + DMI_MATCH(DMI_PRODUCT_NAME, "MSI Notebook VR201"),
>> + },
>> + },
>> + {
>> + .callback = a20_enable_kbc,
>> + .ident = "MSI VR601 Laptop",
>> + .matches = {
>> + DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star International"),
>> + DMI_MATCH(DMI_PRODUCT_NAME, "MSI Notebook VR601"),
>> + },
>> + },
>> + {
>> + .callback = a20_enable_kbc,
>> + .ident = "MSI PR200 Laptop",
>> + .matches = {
>> + DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star International"),
>> + DMI_MATCH(DMI_PRODUCT_NAME, "MSI Notebook PR200"),
>> + },
>> + },
>> {}
>> };
>>
>>
>>
>>

--
Sent from my mobile phone. Please excuse brevity and lack of formatting.
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