1 files changed, 15 insertions, 6 deletions

diff --git a/drivers/acpi/video.c b/drivers/acpi/video.c
index 94b1a4c5abab..05dff631591c 100644
--- a/drivers/acpi/video.c
+++ b/drivers/acpi/video.c
@@ -285,7 +285,7 @@ static int acpi_video_device_brightness_open_fs(struct inode *inode,
                                                 struct file *file);
 static ssize_t acpi_video_device_write_brightness(struct file *file,
         const char __user *buffer, size_t count, loff_t *data);
-static struct file_operations acpi_video_device_brightness_fops = {
+static const struct file_operations acpi_video_device_brightness_fops = {
         .owner = THIS_MODULE,
         .open = acpi_video_device_brightness_open_fs,
         .read = seq_read,
@@ -1109,7 +1109,12 @@ static int acpi_video_bus_check(struct acpi_video_bus *video)
          */
 
         /* Does this device support video switching? */
-        if (video->cap._DOS) {
+        if (video->cap._DOS || video->cap._DOD) {
+                if (!video->cap._DOS) {
+                        printk(KERN_WARNING FW_BUG
+                                "ACPI(%s) defines _DOD but not _DOS\n",
+                                acpi_device_bid(video->device));
+                }
                 video->flags.multihead = 1;
                 status = 0;
         }
@@ -1218,7 +1223,7 @@ acpi_video_device_write_state(struct file *file,
         u32 state = 0;
 
 
-        if (!dev || count + 1 > sizeof str)
+        if (!dev || count >= sizeof(str))
                 return -EINVAL;
 
         if (copy_from_user(str, buffer, count))
@@ -1275,7 +1280,7 @@ acpi_video_device_write_brightness(struct file *file,
         int i;
 
 
-        if (!dev || !dev->brightness || count + 1 > sizeof str)
+        if (!dev || !dev->brightness || count >= sizeof(str))
                 return -EINVAL;
 
         if (copy_from_user(str, buffer, count))
@@ -1557,7 +1562,7 @@ acpi_video_bus_write_POST(struct file *file,
         unsigned long long opt, options;
 
 
-        if (!video || count + 1 > sizeof str)
+        if (!video || count >= sizeof(str))
                 return -EINVAL;
 
         status = acpi_video_bus_POST_options(video, &options);
@@ -1597,7 +1602,7 @@ acpi_video_bus_write_DOS(struct file *file,
         unsigned long opt;
 
 
-        if (!video || count + 1 > sizeof str)
+        if (!video || count >= sizeof(str))
                 return -EINVAL;
 
         if (copy_from_user(str, buffer, count))
@@ -1986,6 +1991,10 @@ acpi_video_switch_brightness(struct acpi_video_device *device, int event)
 
         result = acpi_video_device_lcd_set_level(device, level_next);
 
+        if (!result)
+                backlight_force_update(device->backlight,
+                                       BACKLIGHT_UPDATE_HOTKEY);
+
 out:
         if (result)
                 printk(KERN_ERR PREFIX "Failed to switch the brightness\n");