From b1ca0d42cbeef83bd133155ac88f1b6f09e7e8d6 Mon Sep 17 00:00:00 2001
From: Zhao Yakui <yakui.zhao@intel.com>
Date: Tue, 16 Jun 2009 11:23:13 +0800
Subject: [PATCH] --- yaml --- r: 154161 b: refs/heads/master c:
 86e437f077c68112edcb6854ec036ed7e3f9a7f3 h: refs/heads/master i:   154159:
 646b20e60dcbc6c5b6d167b2f7c944e9150f8375 v: v3

---
 [refs]                                     |  2 +-
 trunk/drivers/acpi/video.c                 | 49 +++++++++++++++-------
 trunk/drivers/gpu/drm/i915/i915_opregion.c |  2 +-
 trunk/include/acpi/video.h                 |  4 +-
 4 files changed, 39 insertions(+), 18 deletions(-)

diff --git a/[refs] b/[refs]
index 7bf5e6d5a55d..fd6502d50dab 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 152a4e630f7ffdd7ff64427c4ba488dc0bce76af
+refs/heads/master: 86e437f077c68112edcb6854ec036ed7e3f9a7f3
diff --git a/trunk/drivers/acpi/video.c b/trunk/drivers/acpi/video.c
index 1eff1625672a..a63566ba230b 100644
--- a/trunk/drivers/acpi/video.c
+++ b/trunk/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);
@@ -586,14 +587,6 @@ 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"),
-		},
-	},
 	{}
 };
 
@@ -2326,6 +2319,13 @@ 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)
@@ -2337,10 +2337,35 @@ 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
@@ -2358,16 +2383,12 @@ 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);
diff --git a/trunk/drivers/gpu/drm/i915/i915_opregion.c b/trunk/drivers/gpu/drm/i915/i915_opregion.c
index dc425e74a268..e4b4e8898e39 100644
--- a/trunk/drivers/gpu/drm/i915/i915_opregion.c
+++ b/trunk/drivers/gpu/drm/i915/i915_opregion.c
@@ -419,7 +419,7 @@ void intel_opregion_free(struct drm_device *dev, int suspend)
 		return;
 
 	if (!suspend)
-		acpi_video_exit();
+		acpi_video_unregister();
 
 	opregion->acpi->drdy = 0;
 
diff --git a/trunk/include/acpi/video.h b/trunk/include/acpi/video.h
index af6fe95fd3d0..cf7be3dd157b 100644
--- a/trunk/include/acpi/video.h
+++ b/trunk/include/acpi/video.h
@@ -3,10 +3,10 @@
 
 #if (defined CONFIG_ACPI_VIDEO || defined CONFIG_ACPI_VIDEO_MODULE)
 extern int acpi_video_register(void);
-extern int acpi_video_exit(void);
+extern void acpi_video_unregister(void);
 #else
 static inline int acpi_video_register(void) { return 0; }
-static inline void acpi_video_exit(void) { return; }
+static inline void acpi_video_unregister(void) { return; }
 #endif
 
 #endif