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@xxxxxxxxxx> Reviewed-by: Daniel Dadap <ddadap@xxxxxxxxxx> Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx> --- 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 be803e47eac0..baccdf658538 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; /* -- 2.37.2