diff --git a/drivers/acpi/acpi_video.c b/drivers/acpi/acpi_video.c index 97b711e57bff..c7a6d0b69dab 100644 --- a/drivers/acpi/acpi_video.c +++ b/drivers/acpi/acpi_video.c @@ -1984,6 +1984,7 @@ static int instance; static int acpi_video_bus_add(struct acpi_device *device) { struct acpi_video_bus *video; + bool auto_detect; int error; acpi_status status; @@ -2045,10 +2046,20 @@ static int acpi_video_bus_add(struct acpi_device *device) mutex_unlock(&video_list_lock); /* - * The userspace visible backlight_device gets registered separately - * from acpi_video_register_backlight(). + * If backlight-type auto-detection is used then a native backlight may + * show up later and this may change the result from video to native. + * Therefor normally the userspace visible /sys/class/backlight device + * gets registered separately by the GPU driver calling + * acpi_video_register_backlight() when an internal panel is detected. + * Register the backlight now when not using auto-detection, so that + * when the kernel cmdline or DMI-quirks are used the backlight will + * get registered even if acpi_video_register_backlight() is not called. */ acpi_video_run_bcl_for_osi(video); + if (__acpi_video_get_backlight_type(false, &auto_detect) == acpi_backlight_video && + !auto_detect) + acpi_video_bus_register_backlight(video); + acpi_video_bus_add_notify_handler(video); return 0;