1 files changed, 42 insertions, 7 deletions

diff --git a/drivers/acpi/video.c b/drivers/acpi/video.c
index bd77e81e81c1..a54ff6bce8fa 100644
--- a/drivers/acpi/video.c
+++ b/drivers/acpi/video.c
@@ -292,18 +292,26 @@ static int acpi_video_device_set_state(struct acpi_video_device *device, int sta
 static int acpi_video_get_brightness(struct backlight_device *bd)
 {
         unsigned long cur_level;
+        int i;
         struct acpi_video_device *vd =
                 (struct acpi_video_device *)bl_get_data(bd);
         acpi_video_device_lcd_get_level_current(vd, &cur_level);
-        return (int) cur_level;
+        for (i = 2; i < vd->brightness->count; i++) {
+                if (vd->brightness->levels[i] == cur_level)
+                        /* The first two entries are special - see page 575
+                           of the ACPI spec 3.0 */
+                        return i-2;
+        }
+        return 0;
 }
 
 static int acpi_video_set_brightness(struct backlight_device *bd)
 {
-        int request_level = bd->props.brightness;
+        int request_level = bd->props.brightness+2;
         struct acpi_video_device *vd =
                 (struct acpi_video_device *)bl_get_data(bd);
-        acpi_video_device_lcd_set_level(vd, request_level);
+        acpi_video_device_lcd_set_level(vd,
+                                        vd->brightness->levels[request_level]);
         return 0;
 }
 
@@ -652,7 +660,6 @@ static void acpi_video_device_find_cap(struct acpi_video_device *device)
         kfree(obj);
 
         if (device->cap._BCL && device->cap._BCM && device->cap._BQC && max_level > 0){
-                unsigned long tmp;
                 static int count = 0;
                 char *name;
                 name = kzalloc(MAX_NAME_LEN, GFP_KERNEL);
@@ -660,11 +667,10 @@ static void acpi_video_device_find_cap(struct acpi_video_device *device)
                         return;
 
                 sprintf(name, "acpi_video%d", count++);
-                acpi_video_device_lcd_get_level_current(device, &tmp);
                 device->backlight = backlight_device_register(name,
                         NULL, device, &acpi_backlight_ops);
-                device->backlight->props.max_brightness = max_level;
-                device->backlight->props.brightness = (int)tmp;
+                device->backlight->props.max_brightness = device->brightness->count-3;
+                device->backlight->props.brightness = acpi_video_get_brightness(device->backlight);
                 backlight_update_status(device->backlight);
 
                 kfree(name);
@@ -1256,8 +1262,37 @@ acpi_video_bus_write_DOS(struct file *file,
 
 static int acpi_video_bus_add_fs(struct acpi_device *device)
 {
+        long device_id;
+        int status;
         struct proc_dir_entry *entry = NULL;
         struct acpi_video_bus *video;
+        struct device *dev;
+
+        status =
+            acpi_evaluate_integer(device->handle, "_ADR", NULL, &device_id);
+
+        if (!ACPI_SUCCESS(status))
+                return -ENODEV;
+
+        /* We need to attempt to determine whether the _ADR refers to a
+           PCI device or not. There's no terribly good way to do this,
+           so the best we can hope for is to assume that there'll never
+           be a video device in the host bridge */
+        if (device_id >= 0x10000) {
+                /* It looks like a PCI device. Does it exist? */
+                dev = acpi_get_physical_device(device->handle);
+        } else {
+                /* It doesn't look like a PCI device. Does its parent
+                   exist? */
+                acpi_handle phandle;
+                if (acpi_get_parent(device->handle, &phandle))
+                        return -ENODEV;
+                dev = acpi_get_physical_device(phandle);
+        }
+        if (!dev)
+                return -ENODEV;
+        put_device(dev);
+
 
 
         video = acpi_driver_data(device);