From: Hans de Goede <hdegoede@xxxxxxxxxx> [ Upstream commit db5e2a4ca0a7a5fe54f410590292ea2e91de6798 ] Thinklight has only two values, on/off so it's reasonable for max_brightness to be 0 and 1 as if you write anything between 0 and 255 it will be 255 anyway so there's no point for it to be 255. This may look like it is a userspace API change, but writes with a value larget then the new max_brightness will still be accepted, these will be silently clamped to the new max_brightness by led_set_brightness_nosleep(). So no userspace API problems are expected. Reported-by: Michał Szczepaniak <m.szczepaniak.000@xxxxxxxxx> Link: https://lore.kernel.org/platform-driver-x86/55400326-e64f-5444-94e5-22b8214d00b6@xxxxxxxxx/ Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/platform/x86/thinkpad_acpi.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/platform/x86/thinkpad_acpi.c b/drivers/platform/x86/thinkpad_acpi.c index 8476dfef4e62..a1d91736a03b 100644 --- a/drivers/platform/x86/thinkpad_acpi.c +++ b/drivers/platform/x86/thinkpad_acpi.c @@ -5572,6 +5572,7 @@ static enum led_brightness light_sysfs_get(struct led_classdev *led_cdev) static struct tpacpi_led_classdev tpacpi_led_thinklight = { .led_classdev = { .name = "tpacpi::thinklight", + .max_brightness = 1, .brightness_set_blocking = &light_sysfs_set, .brightness_get = &light_sysfs_get, } -- 2.35.1