/* Some systems turn the backlight all the way off at the lowest levels.
* clamp_brightness clamps the saved brightness to at least 1 or 5% of
- * max_brightness. This avoids preserving an unreadably dim screen, which
- * would otherwise force the user to disable state restoration. */
+ * max_brightness in case of 'backlight' subsystem. This avoids preserving
+ * an unreadably dim screen, which would otherwise force the user to
+ * disable state restoration. */
static void clamp_brightness(struct udev_device *device, char **value, unsigned max_brightness) {
int r;
unsigned brightness, new_brightness, min_brightness;
+ const char *subsystem;
r = safe_atou(*value, &brightness);
if (r < 0) {
return;
}
- min_brightness = MAX(1U, max_brightness/20);
+ subsystem = udev_device_get_subsystem(device);
+ if (streq_ptr(subsystem, "backlight"))
+ min_brightness = MAX(1U, max_brightness/20);
+ else
+ min_brightness = 0;
+
new_brightness = CLAMP(brightness, min_brightness, max_brightness);
if (new_brightness != brightness) {
char *old_value = *value;
* device probing should be complete), so that the validity
* check at boot time doesn't have to be reliable. */
- if (streq(argv[1], "load") && shall_restore_state()) {
+ if (streq(argv[1], "load")) {
_cleanup_free_ char *value = NULL;
+ if (!shall_restore_state())
+ return EXIT_SUCCESS;
+
if (!validate_device(udev, device))
return EXIT_SUCCESS;