1 files changed, 52 insertions, 9 deletions

diff --git a/drivers/acpi/video.c b/drivers/acpi/video.c
index 1bdfb37377e3..8851315ce858 100644
--- a/drivers/acpi/video.c
+++ b/drivers/acpi/video.c
@@ -76,6 +76,7 @@ MODULE_LICENSE("GPL");
 static int brightness_switch_enabled = 1;
 module_param(brightness_switch_enabled, bool, 0644);
 
+static int register_count = 0;
 static int acpi_video_bus_add(struct acpi_device *device);
 static int acpi_video_bus_remove(struct acpi_device *device, int type);
 static int acpi_video_resume(struct acpi_device *device);
@@ -586,6 +587,14 @@ static struct dmi_system_id video_dmi_table[] __initdata = {
                 DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5315"),
                 },
         },
+        {
+         .callback = video_set_bqc_offset,
+         .ident = "Acer Aspire 7720",
+         .matches = {
+                DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
+                DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 7720"),
+                },
+        },
         {}
 };
 
@@ -976,6 +985,11 @@ static void acpi_video_device_find_cap(struct acpi_video_device *device)
                 device->backlight->props.max_brightness = device->brightness->count-3;
                 kfree(name);
 
+                result = sysfs_create_link(&device->backlight->dev.kobj,
+                                           &device->dev->dev.kobj, "device");
+                if (result)
+                        printk(KERN_ERR PREFIX "Create sysfs link\n");
+
                 device->cdev = thermal_cooling_device_register("LCD",
                                         device->dev, &video_cooling_ops);
                 if (IS_ERR(device->cdev))
@@ -1054,15 +1068,15 @@ static void acpi_video_bus_find_cap(struct acpi_video_bus *video)
 static int acpi_video_bus_check(struct acpi_video_bus *video)
 {
         acpi_status status = -ENOENT;
-        struct device *dev;
+        struct pci_dev *dev;
 
         if (!video)
                 return -EINVAL;
 
-        dev = acpi_get_physical_pci_device(video->device->handle);
+        dev = acpi_get_pci_dev(video->device->handle);
         if (!dev)
                 return -ENODEV;
-        put_device(dev);
+        pci_dev_put(dev);
 
         /* Since there is no HID, CID and so on for VGA driver, we have
          * to check well known required nodes.
@@ -1990,6 +2004,7 @@ static int acpi_video_bus_put_one_device(struct acpi_video_device *device)
         status = acpi_remove_notify_handler(device->dev->handle,
                                             ACPI_DEVICE_NOTIFY,
                                             acpi_video_device_notify);
+        sysfs_remove_link(&device->backlight->dev.kobj, "device");
         backlight_device_unregister(device->backlight);
         if (device->cdev) {
                 sysfs_remove_link(&device->dev->dev.kobj,
@@ -2318,6 +2333,13 @@ static int __init intel_opregion_present(void)
 int acpi_video_register(void)
 {
         int result = 0;
+        if (register_count) {
+                /*
+                 * if the function of acpi_video_register is already called,
+                 * don't register the acpi_vide_bus again and return no error.
+                 */
+                return 0;
+        }
 
         acpi_video_dir = proc_mkdir(ACPI_VIDEO_CLASS, acpi_root_dir);
         if (!acpi_video_dir)
@@ -2329,10 +2351,35 @@ int acpi_video_register(void)
                 return -ENODEV;
         }
 
+        /*
+         * When the acpi_video_bus is loaded successfully, increase
+         * the counter reference.
+         */
+        register_count = 1;
+
         return 0;
 }
 EXPORT_SYMBOL(acpi_video_register);
 
+void acpi_video_unregister(void)
+{
+        if (!register_count) {
+                /*
+                 * If the acpi video bus is already unloaded, don't
+                 * unload it again and return directly.
+                 */
+                return;
+        }
+        acpi_bus_unregister_driver(&acpi_video_bus);
+
+        remove_proc_entry(ACPI_VIDEO_CLASS, acpi_root_dir);
+
+        register_count = 0;
+
+        return;
+}
+EXPORT_SYMBOL(acpi_video_unregister);
+
 /*
  * This is kind of nasty. Hardware using Intel chipsets may require
  * the video opregion code to be run first in order to initialise
@@ -2350,16 +2397,12 @@ static int __init acpi_video_init(void)
         return acpi_video_register();
 }
 
-void acpi_video_exit(void)
+static void __exit acpi_video_exit(void)
 {
-
-        acpi_bus_unregister_driver(&acpi_video_bus);
-
-        remove_proc_entry(ACPI_VIDEO_CLASS, acpi_root_dir);
+        acpi_video_unregister();
 
         return;
 }
-EXPORT_SYMBOL(acpi_video_exit);
 
 module_init(acpi_video_init);
 module_exit(acpi_video_exit);