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-rw-r--r--src/backlight/backlight.c13
1 files changed, 10 insertions, 3 deletions
diff --git a/src/backlight/backlight.c b/src/backlight/backlight.c
index 691472cc3a..4d94ebf58a 100644
--- a/src/backlight/backlight.c
+++ b/src/backlight/backlight.c
@@ -225,11 +225,13 @@ static unsigned get_max_brightness(struct udev_device *device) {
/* 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) {
@@ -237,7 +239,12 @@ static void clamp_brightness(struct udev_device *device, char **value, unsigned
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;