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>

1 files changed, 12 insertions, 1 deletions

diff --git a/drivers/acpi/video.c b/drivers/acpi/video.c
index 83aa41c5c59f..8a60a3d7001c 100644
--- a/drivers/acpi/video.c
+++ b/drivers/acpi/video.c
@@ -1636,9 +1636,20 @@ 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)