[PATCH v3 19/31] platform/x86: nvidia-wmi-ec-backlight: Use acpi_video_get_backlight_type()

[Daniel Dadap]

On 8/18/22 1:42 PM, Hans de Goede wrote:
> Add an acpi_video_get_backlight_type() == acpi_backlight_nvidia_wmi_ec
> check. This will make nvidia-wmi-ec-backlight properly honor the user
> selecting a different backlight driver through the acpi_backlight=...
> kernel commandline option.
>
> Since the auto-detect code check for nvidia-wmi-ec-backlight in
> drivers/acpi/video_detect.c already checks that the WMI advertised
> brightness-source is the embedded controller, this new check makes it
> unnecessary for nvidia_wmi_ec_backlight_probe() to check this itself.
>
> Suggested-by: Daniel Dadap <ddadap at nvidia.com>
> Signed-off-by: Hans de Goede <hdegoede at redhat.com>
> ---
>   drivers/platform/x86/Kconfig                   |  1 +
>   drivers/platform/x86/nvidia-wmi-ec-backlight.c | 14 +++-----------
>   2 files changed, 4 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
> index f2f98e942cf2..0cc5ac35fc57 100644
> --- a/drivers/platform/x86/Kconfig
> +++ b/drivers/platform/x86/Kconfig
> @@ -93,6 +93,7 @@ config PEAQ_WMI
>   
>   config NVIDIA_WMI_EC_BACKLIGHT
>   	tristate "EC Backlight Driver for Hybrid Graphics Notebook Systems"
> +	depends on ACPI_VIDEO
>   	depends on ACPI_WMI
>   	depends on BACKLIGHT_CLASS_DEVICE
>   	help
> diff --git a/drivers/platform/x86/nvidia-wmi-ec-backlight.c b/drivers/platform/x86/nvidia-wmi-ec-backlight.c
> index e84e1d629b14..83d544180264 100644
> --- a/drivers/platform/x86/nvidia-wmi-ec-backlight.c
> +++ b/drivers/platform/x86/nvidia-wmi-ec-backlight.c
> @@ -10,6 +10,7 @@
>   #include <linux/platform_data/x86/nvidia-wmi-ec-backlight.h>
>   #include <linux/types.h>
>   #include <linux/wmi.h>
> +#include <acpi/video.h>
>   
>   /**
>    * wmi_brightness_notify() - helper function for calling WMI-wrapped ACPI method
> @@ -87,19 +88,10 @@ static int nvidia_wmi_ec_backlight_probe(struct wmi_device *wdev, const void *ct
>   {
>   	struct backlight_properties props = {};
>   	struct backlight_device *bdev;
> -	u32 source;
>   	int ret;
>   
> -	ret = wmi_brightness_notify(wdev, WMI_BRIGHTNESS_METHOD_SOURCE,
> -	                           WMI_BRIGHTNESS_MODE_GET, &source);
> -	if (ret)
> -		return ret;
> -
> -	/*
> -	 * This driver is only to be used when brightness control is handled
> -	 * by the EC; otherwise, the GPU driver(s) should control brightness.
> -	 */
> -	if (source != WMI_BRIGHTNESS_SOURCE_EC)
> +	/* drivers/acpi/video_detect.c also checks that SOURCE == EC */
> +	if (acpi_video_get_backlight_type() != acpi_backlight_nvidia_wmi_ec)
>   		return -ENODEV;
>   
>   	/*


Reviewed-by: Daniel Dadap <ddadap at nvidia.com>