===================================================================
@@ -80,6 +80,13 @@ module_param(brightness_switch_enabled,
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_v
* 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;
}