Re: [PATCH 10/15] acpi: Export acpi_bus_type

From: Rafael J. Wysocki
Date: Tue Aug 30 2016 - 18:47:45 EST


On Tue, Aug 30, 2016 at 6:49 PM, <jeff.mcgee@xxxxxxxxx> wrote:
> From: Ankitprasad Sharma <ankitprasad.r.sharma@xxxxxxxxx>
>
> Some modules, like i915.ko, needs to detect when certain ACPI features are
> active inorder to prevent corruption on contended resources.
> In particular, use of BIOS RapidStart Technology may corrupt the contents of
> the reserved graphics memory, due to unalarmed hibernation. In which case
> i915.ko cannot assume that it (reserved gfx memory) remains unmodified and
> must recreate the contents and importantly not use it to store unrecoverable
> user data.

The above doesn't explain why you need to export acpi_bus_type at all.

I suspect that this is in order to be able to do some hackish stuff on
it, so I'm not going to approve this patch as is.

> Signed-off-by: Ankitprasad Sharma <ankitprasad.r.sharma@xxxxxxxxx>
> Cc: "Rafael J. Wysocki" <rjw@xxxxxxxxxxxxx>
> Cc: Len Brown <lenb@xxxxxxxxxx>
> Cc: linux-acpi@xxxxxxxxxxxxxxx
> Cc: linux-kernel@xxxxxxxxxxxxxxx
> Signed-off-by: Jeff McGee <jeff.mcgee@xxxxxxxxx>
> ---
> drivers/acpi/scan.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
> index 4b22ea8..7461bab 100644
> --- a/drivers/acpi/scan.c
> +++ b/drivers/acpi/scan.c
> @@ -1269,6 +1269,7 @@ struct bus_type acpi_bus_type = {
> .remove = acpi_device_remove,
> .uevent = acpi_device_uevent,
> };
> +EXPORT_SYMBOL_GPL(acpi_bus_type);
>
> static void acpi_device_del(struct acpi_device *device)
> {
> --

Thanks,
Rafael