1 files changed, 20 insertions, 0 deletions

diff --git a/drivers/acpi/video.c b/drivers/acpi/video.c
index baa441929720..f261737636da 100644
--- a/drivers/acpi/video.c
+++ b/drivers/acpi/video.c
@@ -36,6 +36,7 @@
 #include <linux/backlight.h>
 #include <linux/thermal.h>
 #include <linux/video_output.h>
+#include <linux/sort.h>
 #include <asm/uaccess.h>
 
 #include <acpi/acpi_bus.h>
@@ -481,6 +482,7 @@ acpi_video_device_lcd_set_level(struct acpi_video_device *device, int level)
         int status = AE_OK;
         union acpi_object arg0 = { ACPI_TYPE_INTEGER };
         struct acpi_object_list args = { 1, &arg0 };
+        int state;
 
 
         arg0.integer.value = level;
@@ -489,6 +491,10 @@ acpi_video_device_lcd_set_level(struct acpi_video_device *device, int level)
                 status = acpi_evaluate_object(device->dev->handle, "_BCM",
                                               &args, NULL);
         device->brightness->curr = level;
+        for (state = 2; state < device->brightness->count; state++)
+                if (level == device->brightness->levels[state])
+                        device->backlight->props.brightness = state - 2;
+
         return status;
 }
 
@@ -626,6 +632,16 @@ acpi_video_bus_DOS(struct acpi_video_bus *video, int bios_flag, int lcd_flag)
 }
 
 /*
+ * Simple comparison function used to sort backlight levels.
+ */
+
+static int
+acpi_video_cmp_level(const void *a, const void *b)
+{
+        return *(int *)a - *(int *)b;
+}
+
+/*
  *  Arg:        
  *      device  : video output device (LCD, CRT, ..)
  *
@@ -676,6 +692,10 @@ acpi_video_init_brightness(struct acpi_video_device *device)
                 count++;
         }
 
+        /* don't sort the first two brightness levels */
+        sort(&br->levels[2], count - 2, sizeof(br->levels[2]),
+                acpi_video_cmp_level, NULL);
+
         if (count < 2)
                 goto out_free_levels;