Re: [PATCH] ACPI / video: Do not bind to device objects with a driver or scan handler

Aaron Lu
2013-06-09T00:33:28Z

On 06/08/2013 10:14 PM, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
>
> With the introduction of ACPI scan handlers, ACPI device objects
> with an ACPI scan handler attached to them must not be bound to
> an ACPI driver any more. Unfortunately, however, the ACPI video
> driver attempts to do just that if there is a _ROM ACPI control
> method defined under a device object with an ACPI scan handler.
>
> Prevent that from happening by making the video driver's "add"
> routine check if the device object already has a driver or
> ACPI scan handler attached to it and return an error code in
> that case. That is not sufficient, though, because
> acpi_bus_driver_init() would then clear the device object's
> driver_data that may be set by the scan handler attached to it,
> so for the fix to work acpi_bus_driver_init() has to be modified
> to leave driver_data as is on errors.

Reviewed-by: Aaron Lu <aaron.lu@intel.com>

Thanks,
Aaron

>
> References: https://bugzilla.kernel.org/show_bug.cgi?id=58091
> Reported-and-bisected-by: Dmitry S. Demin <dmitryy.demin@gmail.com>
> Reported-and-tested-by: Jason Cassell <bluesloth600@gmail.com>
> Tracked-down-by: Aaron Lu <aaron.lu@intel.com>
> Cc: 3.9+ <stable@kernel.org>
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> ---
> drivers/acpi/scan.c | 5 +----
> drivers/acpi/video.c | 3 +++
> 2 files changed, 4 insertions(+), 4 deletions(-)
>
> Index: linux-pm/drivers/acpi/video.c
> ===================================================================
> --- linux-pm.orig/drivers/acpi/video.c
> +++ linux-pm/drivers/acpi/video.c
> @@ -1722,6 +1722,9 @@ static int acpi_video_bus_add(struct acp
> int error;
> acpi_status status;
>
> + if (device->handler || device->driver)
> + return -EINVAL;
> +
> status = acpi_walk_namespace(ACPI_TYPE_DEVICE,
> device->parent->handle, 1,
> acpi_video_bus_match, NULL,
> Index: linux-pm/drivers/acpi/scan.c
> ===================================================================
> --- linux-pm.orig/drivers/acpi/scan.c
> +++ linux-pm/drivers/acpi/scan.c
> @@ -1133,11 +1133,8 @@ acpi_bus_driver_init(struct acpi_device
> return -ENOSYS;
>
> result = driver->ops.add(device);
> - if (result) {
> - device->driver = NULL;
> - device->driver_data = NULL;
> + if (result)
> return result;
> - }
>
> device->driver = driver;
>
>