Re: [RFC Patch 08/19] ACPI: Add prefetch decoding to the address space parser

[Jiang Liu]

On 2015/1/21 8:35, Rafael J. Wysocki wrote:
> On Thursday, January 08, 2015 10:32:55 AM Jiang Liu wrote:
>> From: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
>>
>> Add support of PREFETCH attributre to ACPI address space and extended
>> address space parser.
> 
> This potentially enables untested configurations which tends to uncover bugs,
> so I'm concerned.
> 
> What's the possible impact of this?
Hi Rafael,
	I have analyzed all call sites related to this change, most
users just care about resource type(IO, MEM, IRQ etc) and ignore
the prefetch property. Seems only PCI subsystem cares about PREFETCH.
Regards,
Gerry

> 
>> Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
>> Signed-off-by: Jiang Liu <jiang.liu@xxxxxxxxxxxxxxx>
>> ---
>>  drivers/acpi/resource.c |    3 +++
>>  1 file changed, 3 insertions(+)
>>
>> diff --git a/drivers/acpi/resource.c b/drivers/acpi/resource.c
>> index a56a64164410..abe3a29ad802 100644
>> --- a/drivers/acpi/resource.c
>> +++ b/drivers/acpi/resource.c
>> @@ -200,6 +200,9 @@ static bool acpi_decode_space(struct resource *res,
>>  	if (base->producer_consumer == ACPI_PRODUCER)
>>  		res->flags |= IORESOURCE_WINDOW;
>>  
>> +	if (base->info.mem.caching == ACPI_PREFETCHABLE_MEMORY)
>> +		res->flags |= IORESOURCE_PREFETCH;
>> +
>>  	return !(res->flags & IORESOURCE_DISABLED);
>>  }
>>  
>>
> 
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