[PATCH 10/15] acpi: Export acpi_bus_type

[PATCH 10/15] acpi: Export acpi_bus_type

[jeff.mcgee]

From: Ankitprasad Sharma <ankitprasad.r.sharma@intel.com>

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.

Signed-off-by: Ankitprasad Sharma <ankitprasad.r.sharma@intel.com>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Len Brown <lenb@kernel.org>
Cc: linux-acpi@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Jeff McGee <jeff.mcgee@intel.com>
---
 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)
 {
-- 
2.9.3

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

[Rafael J. Wysocki]

On Tue, Aug 30, 2016 at 6:49 PM,  <jeff.mcgee@intel.com> wrote:
> From: Ankitprasad Sharma <ankitprasad.r.sharma@intel.com>
>
> 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@intel.com>
> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
> Cc: Len Brown <lenb@kernel.org>
> Cc: linux-acpi@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org
> Signed-off-by: Jeff McGee <jeff.mcgee@intel.com>
> ---
>  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

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

[Jeff McGee]

On Wed, Aug 31, 2016 at 12:47:39AM +0200, Rafael J. Wysocki wrote:
> On Tue, Aug 30, 2016 at 6:49 PM,  <jeff.mcgee@intel.com> wrote:
> > From: Ankitprasad Sharma <ankitprasad.r.sharma@intel.com>
> >
> > 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.
> 

My apologies. I was forwarding this collection internally with git send-mail
but didn't scrub the original patch cc list. Please disregard.

> > Signed-off-by: Ankitprasad Sharma <ankitprasad.r.sharma@intel.com>
> > Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
> > Cc: Len Brown <lenb@kernel.org>
> > Cc: linux-acpi@vger.kernel.org
> > Cc: linux-kernel@vger.kernel.org
> > Signed-off-by: Jeff McGee <jeff.mcgee@intel.com>
> > ---
> >  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