Re: [PATCH 1/2] acpi: don't free non-existant backlight in acpi video module

[Zhang Rui <rui.zhang@intel.com>]

On Sun, 2009-07-12 at 14:47 +0800, keithp@keithp.com wrote:
> From: Keith Packard <keithp@keithp.com>
> 
> acpi_video_put_one_device was attempting to remove sysfs entries and
> unregister a backlight device without first checking that said backlight
> device structure had been created.
> 
> Signed-off-by: Keith Packard <keithp@keithp.com>

Acked-by: Zhang Rui <rui.zhang@intel.com>

> ---
>  drivers/acpi/video.c |    7 +++++--
>  1 files changed, 5 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/acpi/video.c b/drivers/acpi/video.c
> index 8851315..60ea984 100644
> --- a/drivers/acpi/video.c
> +++ b/drivers/acpi/video.c
> @@ -2004,8 +2004,11 @@ static int acpi_video_bus_put_one_device(struct acpi_video_device *device)
>  	status = acpi_remove_notify_handler(device->dev->handle,
>  					    ACPI_DEVICE_NOTIFY,
>  					    acpi_video_device_notify);
> -	sysfs_remove_link(&device->backlight->dev.kobj, "device");
> -	backlight_device_unregister(device->backlight);
> +	if (device->backlight) {
> +		sysfs_remove_link(&device->backlight->dev.kobj, "device");
> +		backlight_device_unregister(device->backlight);
> +		device->backlight = NULL;
> +	}
>  	if (device->cdev) {
>  		sysfs_remove_link(&device->dev->dev.kobj,
>  				  "thermal_cooling");