Re: [RFC PATCH 2/4] ACPI/Resource: Add address translation support

From: Rafael J. Wysocki
Date: Fri Sep 06 2013 - 20:04:16 EST


On Friday, September 06, 2013 10:24:44 AM Lan Tianyu wrote:
> According ACPI 5.0 spec Section 19.1.8
> "For bridges, translate addresses across the bridge, this is the
> offset that must be added to the address on the secondary side
> to obtain the address on the primary side. Non-bridge devices
> must list 0."

Can you please have a look into the previous versions of the spec and double
check that this change won't confuse systems that implement them?

Otherwise it looks OK to me.

Thanks,
Rafael


> This patch is to add address translation offset to the start/end
> of struct resource in the acpi_dev_resource_address_space().
> Further more, non-bridge device's translation_offset should 0.
> So this change will affect other devices.
>
>
> Signed-off-by: Lan Tianyu <tianyu.lan@xxxxxxxxx>
> ---
> drivers/acpi/resource.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/acpi/resource.c b/drivers/acpi/resource.c
> index 929f416..84bc3db 100644
> --- a/drivers/acpi/resource.c
> +++ b/drivers/acpi/resource.c
> @@ -192,8 +192,8 @@ bool acpi_dev_resource_address_space(struct acpi_resource *ares,
> if (ACPI_FAILURE(status))
> return true;
>
> - res->start = addr.minimum;
> - res->end = addr.maximum;
> + res->start = addr.minimum + addr.translation_offset;
> + res->end = addr.maximum + addr.translation_offset;
> window = addr.producer_consumer == ACPI_PRODUCER;
>
> switch(addr.resource_type) {
>
--
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/