ACPI: VIDEO: Adjust current level to closest available one.

patch 63f0edfc in mainline.

ACPI: VIDEO: Adjust current level to closest available one.
Signed-off-by: Alexey Starikovskiy <astarikovskiy@suse.de>
Signed-off-by: Len Brown <len.brown@intel.com>
Cc: Tobias Powalowski <t.powa@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/acpi/video.c

@@ -1633,9 +1633,20 @@ static int
 acpi_video_get_next_level(struct acpi_video_device *device,
 			  u32 level_current, u32 event)
 {
-	int min, max, min_above, max_below, i, l;
+	int min, max, min_above, max_below, i, l, delta = 255;
 	max = max_below = 0;
 	min = min_above = 255;
+	/* Find closest level to level_current */
+	for (i = 0; i < device->brightness->count; i++) {
+		l = device->brightness->levels[i];
+		if (abs(l - level_current) < abs(delta)) {
+			delta = l - level_current;
+			if (!delta)
+				break;
+		}
+	}
+	/* Ajust level_current to closest available level */
+	level_current += delta;
 	for (i = 0; i < device->brightness->count; i++) {
 		l = device->brightness->levels[i];
 		if (l < min)