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

["H. Peter Anvin" <hpa@zytor.com>]

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

"Rafael J. Wysocki" <rjw@sisk.pl> 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@rainbow-software.org>
>
>Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
>
>
>> --- 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@vger.kernel.org
>>   */
>> @@ -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"),
>> +		     },
>> +	 },
>>  	{}
>>  };
>>  
>> 
>> 
>> 

-- 
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