diff --git a/drivers/acpi/video.c b/drivers/acpi/video.c index 177b4ddc3479..9f8c465d381b 100644 --- a/drivers/acpi/video.c +++ b/drivers/acpi/video.c @@ -80,6 +80,13 @@ module_param(brightness_switch_enabled, bool, 0644); static int allow_duplicates; module_param(allow_duplicates, bool, 0644); +/* + * Some BIOSes claim they use minimum backlight at boot, + * and this may bring dimming screen after boot + */ +static int use_bios_initial_backlight = 1; +module_param(use_bios_initial_backlight, bool, 0644); + static int register_count = 0; static int acpi_video_bus_add(struct acpi_device *device); static int acpi_video_bus_remove(struct acpi_device *device, int type); @@ -705,9 +712,11 @@ acpi_video_init_brightness(struct acpi_video_device *device) * when invoked for the first time, i.e. level_old is invalid. * set the backlight to max_level in this case */ - for (i = 2; i < br->count; i++) - if (level_old == br->levels[i]) - level = level_old; + if (use_bios_initial_backlight) { + for (i = 2; i < br->count; i++) + if (level_old == br->levels[i]) + level = level_old; + } goto set_level; }