9 files changed, 137 insertions, 28 deletions

diff --git a/drivers/acpi/acpica/aclocal.h b/drivers/acpi/acpica/aclocal.h
index dfed26545ba2..d4a4901637cd 100644
--- a/drivers/acpi/acpica/aclocal.h
+++ b/drivers/acpi/acpica/aclocal.h
@@ -931,19 +931,6 @@ struct acpi_bit_register_info {
 
 /* Structs and definitions for _OSI support and I/O port validation */
 
-#define ACPI_OSI_WIN_2000               0x01
-#define ACPI_OSI_WIN_XP                 0x02
-#define ACPI_OSI_WIN_XP_SP1             0x03
-#define ACPI_OSI_WINSRV_2003            0x04
-#define ACPI_OSI_WIN_XP_SP2             0x05
-#define ACPI_OSI_WINSRV_2003_SP1        0x06
-#define ACPI_OSI_WIN_VISTA              0x07
-#define ACPI_OSI_WINSRV_2008            0x08
-#define ACPI_OSI_WIN_VISTA_SP1          0x09
-#define ACPI_OSI_WIN_VISTA_SP2          0x0A
-#define ACPI_OSI_WIN_7                  0x0B
-#define ACPI_OSI_WIN_8                  0x0C
-
 #define ACPI_ALWAYS_ILLEGAL             0x00
 
 struct acpi_interface_info {
diff --git a/drivers/acpi/internal.h b/drivers/acpi/internal.h
index 3a50a34fe176..227aca77ee1e 100644
--- a/drivers/acpi/internal.h
+++ b/drivers/acpi/internal.h
@@ -164,4 +164,15 @@ struct platform_device;
 int acpi_create_platform_device(struct acpi_device *adev,
                                 const struct acpi_device_id *id);
 
+/*--------------------------------------------------------------------------
+                                        Video
+  -------------------------------------------------------------------------- */
+#if defined(CONFIG_ACPI_VIDEO) || defined(CONFIG_ACPI_VIDEO_MODULE)
+bool acpi_video_backlight_quirks(void);
+bool acpi_video_verify_backlight_support(void);
+#else
+static inline bool acpi_video_backlight_quirks(void) { return false; }
+static inline bool acpi_video_verify_backlight_support(void) { return false; }
+#endif
+
 #endif /* _ACPI_INTERNAL_H_ */
diff --git a/drivers/acpi/video.c b/drivers/acpi/video.c
index e441876f5d5b..6dd237e79b4f 100644
--- a/drivers/acpi/video.c
+++ b/drivers/acpi/video.c
@@ -44,6 +44,8 @@
 #include <linux/suspend.h>
 #include <acpi/video.h>
 
+#include "internal.h"
+
 #define PREFIX "ACPI: "
 
 #define ACPI_VIDEO_BUS_NAME             "Video Bus"
@@ -906,7 +908,10 @@ static void acpi_video_device_find_cap(struct acpi_video_device *device)
                 device->cap._DDC = 1;
         }
 
-        if (acpi_video_backlight_support()) {
+        if (acpi_video_init_brightness(device))
+                return;
+
+        if (acpi_video_verify_backlight_support()) {
                 struct backlight_properties props;
                 struct pci_dev *pdev;
                 acpi_handle acpi_parent;
@@ -915,9 +920,6 @@ static void acpi_video_device_find_cap(struct acpi_video_device *device)
                 static int count = 0;
                 char *name;
 
-                result = acpi_video_init_brightness(device);
-                if (result)
-                        return;
                 name = kasprintf(GFP_KERNEL, "acpi_video%d", count);
                 if (!name)
                         return;
@@ -977,6 +979,11 @@ static void acpi_video_device_find_cap(struct acpi_video_device *device)
                 if (result)
                         printk(KERN_ERR PREFIX "Create sysfs link\n");
 
+        } else {
+                /* Remove the brightness object. */
+                kfree(device->brightness->levels);
+                kfree(device->brightness);
+                device->brightness = NULL;
         }
 }
 
@@ -1359,8 +1366,8 @@ acpi_video_switch_brightness(struct acpi_video_device *device, int event)
         unsigned long long level_current, level_next;
         int result = -EINVAL;
 
-        /* no warning message if acpi_backlight=vendor is used */
-        if (!acpi_video_backlight_support())
+        /* no warning message if acpi_backlight=vendor or a quirk is used */
+        if (!acpi_video_verify_backlight_support())
                 return 0;
 
         if (!device->brightness)
@@ -1540,14 +1547,20 @@ static int acpi_video_bus_put_devices(struct acpi_video_bus *video)
 
 /* acpi_video interface */
 
+/*
+ * Win8 requires setting bit2 of _DOS to let firmware know it shouldn't
+ * preform any automatic brightness change on receiving a notification.
+ */
 static int acpi_video_bus_start_devices(struct acpi_video_bus *video)
 {
-        return acpi_video_bus_DOS(video, 0, 0);
+        return acpi_video_bus_DOS(video, 0,
+                                  acpi_video_backlight_quirks() ? 1 : 0);
 }
 
 static int acpi_video_bus_stop_devices(struct acpi_video_bus *video)
 {
-        return acpi_video_bus_DOS(video, 0, 1);
+        return acpi_video_bus_DOS(video, 0,
+                                  acpi_video_backlight_quirks() ? 0 : 1);
 }
 
 static void acpi_video_bus_notify(struct acpi_device *device, u32 event)
@@ -1862,6 +1875,46 @@ static int acpi_video_bus_remove(struct acpi_device *device)
         return 0;
 }
 
+static acpi_status video_unregister_backlight(acpi_handle handle, u32 lvl,
+                                              void *context, void **rv)
+{
+        struct acpi_device *acpi_dev;
+        struct acpi_video_bus *video;
+        struct acpi_video_device *dev, *next;
+
+        if (acpi_bus_get_device(handle, &acpi_dev))
+                return AE_OK;
+
+        if (acpi_match_device_ids(acpi_dev, video_device_ids))
+                return AE_OK;
+
+        video = acpi_driver_data(acpi_dev);
+        if (!video)
+                return AE_OK;
+
+        acpi_video_bus_stop_devices(video);
+        mutex_lock(&video->device_list_lock);
+        list_for_each_entry_safe(dev, next, &video->video_device_list, entry) {
+                if (dev->backlight) {
+                        backlight_device_unregister(dev->backlight);
+                        dev->backlight = NULL;
+                        kfree(dev->brightness->levels);
+                        kfree(dev->brightness);
+                }
+                if (dev->cooling_dev) {
+                        sysfs_remove_link(&dev->dev->dev.kobj,
+                                          "thermal_cooling");
+                        sysfs_remove_link(&dev->cooling_dev->device.kobj,
+                                          "device");
+                        thermal_cooling_device_unregister(dev->cooling_dev);
+                        dev->cooling_dev = NULL;
+                }
+        }
+        mutex_unlock(&video->device_list_lock);
+        acpi_video_bus_start_devices(video);
+        return AE_OK;
+}
+
 static int __init is_i740(struct pci_dev *dev)
 {
         if (dev->device == 0x00D1)
@@ -1893,14 +1946,25 @@ static int __init intel_opregion_present(void)
         return opregion;
 }
 
-int acpi_video_register(void)
+int __acpi_video_register(bool backlight_quirks)
 {
-        int result = 0;
+        bool no_backlight;
+        int result;
+
+        no_backlight = backlight_quirks ? acpi_video_backlight_quirks() : false;
+
         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.
+                 * If acpi_video_register() has been called already, don't try
+                 * to register acpi_video_bus, but unregister backlight devices
+                 * if no backlight support is requested.
                  */
+                if (no_backlight)
+                        acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
+                                            ACPI_UINT32_MAX,
+                                            video_unregister_backlight,
+                                            NULL, NULL, NULL);
+
                 return 0;
         }
 
@@ -1916,7 +1980,7 @@ int acpi_video_register(void)
 
         return 0;
 }
-EXPORT_SYMBOL(acpi_video_register);
+EXPORT_SYMBOL(__acpi_video_register);
 
 void acpi_video_unregister(void)
 {
diff --git a/drivers/acpi/video_detect.c b/drivers/acpi/video_detect.c
index e6bd910bc6ed..826e52def080 100644
--- a/drivers/acpi/video_detect.c
+++ b/drivers/acpi/video_detect.c
@@ -38,6 +38,8 @@
 #include <linux/dmi.h>
 #include <linux/pci.h>
 
+#include "internal.h"
+
 #define PREFIX "ACPI: "
 
 ACPI_MODULE_NAME("video");
@@ -234,6 +236,17 @@ static void acpi_video_caps_check(void)
                 acpi_video_get_capabilities(NULL);
 }
 
+bool acpi_video_backlight_quirks(void)
+{
+        if (acpi_gbl_osi_data >= ACPI_OSI_WIN_8) {
+                acpi_video_caps_check();
+                acpi_video_support |= ACPI_VIDEO_SKIP_BACKLIGHT;
+                return true;
+        }
+        return false;
+}
+EXPORT_SYMBOL(acpi_video_backlight_quirks);
+
 /* Promote the vendor interface instead of the generic video module.
  * This function allow DMI blacklists to be implemented by externals
  * platform drivers instead of putting a big blacklist in video_detect.c
@@ -278,6 +291,14 @@ int acpi_video_backlight_support(void)
 }
 EXPORT_SYMBOL(acpi_video_backlight_support);
 
+/* For the ACPI video driver use only. */
+bool acpi_video_verify_backlight_support(void)
+{
+        return (acpi_video_support & ACPI_VIDEO_SKIP_BACKLIGHT) ?
+                false : acpi_video_backlight_support();
+}
+EXPORT_SYMBOL(acpi_video_verify_backlight_support);
+
 /*
  * Use acpi_backlight=vendor/video to force that backlight switching
  * is processed by vendor specific acpi drivers or video.ko driver.
diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c
index adb319b53ecd..cf188ab7051a 100644
--- a/drivers/gpu/drm/i915/i915_dma.c
+++ b/drivers/gpu/drm/i915/i915_dma.c
@@ -1648,7 +1648,7 @@ int i915_driver_load(struct drm_device *dev, unsigned long flags)
         if (INTEL_INFO(dev)->num_pipes) {
                 /* Must be done after probing outputs */
                 intel_opregion_init(dev);
-                acpi_video_register();
+                acpi_video_register_with_quirks();
         }
 
         if (IS_GEN5(dev))
diff --git a/include/acpi/acpixf.h b/include/acpi/acpixf.h
index 1b09300810e6..22d497ee6ef9 100644
--- a/include/acpi/acpixf.h
+++ b/include/acpi/acpixf.h
@@ -62,6 +62,7 @@ extern u32 acpi_current_gpe_count;
 extern struct acpi_table_fadt acpi_gbl_FADT;
 extern u8 acpi_gbl_system_awake_and_running;
 extern u8 acpi_gbl_reduced_hardware;    /* ACPI 5.0 */
+extern u8 acpi_gbl_osi_data;
 
 /* Runtime configuration of debug print levels */
 
diff --git a/include/acpi/actypes.h b/include/acpi/actypes.h
index a64adcc29ae5..22b03c9286e9 100644
--- a/include/acpi/actypes.h
+++ b/include/acpi/actypes.h
@@ -1144,4 +1144,19 @@ struct acpi_memory_list {
 #endif
 };
 
+/* Definitions for _OSI support */
+
+#define ACPI_OSI_WIN_2000               0x01
+#define ACPI_OSI_WIN_XP                 0x02
+#define ACPI_OSI_WIN_XP_SP1             0x03
+#define ACPI_OSI_WINSRV_2003            0x04
+#define ACPI_OSI_WIN_XP_SP2             0x05
+#define ACPI_OSI_WINSRV_2003_SP1        0x06
+#define ACPI_OSI_WIN_VISTA              0x07
+#define ACPI_OSI_WINSRV_2008            0x08
+#define ACPI_OSI_WIN_VISTA_SP1          0x09
+#define ACPI_OSI_WIN_VISTA_SP2          0x0A
+#define ACPI_OSI_WIN_7                  0x0B
+#define ACPI_OSI_WIN_8                  0x0C
+
 #endif                          /* __ACTYPES_H__ */
diff --git a/include/acpi/video.h b/include/acpi/video.h
index 61109f2609fc..b26dc4fb7ba8 100644
--- a/include/acpi/video.h
+++ b/include/acpi/video.h
@@ -17,12 +17,21 @@ struct acpi_device;
 #define ACPI_VIDEO_DISPLAY_LEGACY_TV      0x0200
 
 #if (defined CONFIG_ACPI_VIDEO || defined CONFIG_ACPI_VIDEO_MODULE)
-extern int acpi_video_register(void);
+extern int __acpi_video_register(bool backlight_quirks);
+static inline int acpi_video_register(void)
+{
+        return __acpi_video_register(false);
+}
+static inline int acpi_video_register_with_quirks(void)
+{
+        return __acpi_video_register(true);
+}
 extern void acpi_video_unregister(void);
 extern int acpi_video_get_edid(struct acpi_device *device, int type,
                                int device_id, void **edid);
 #else
 static inline int acpi_video_register(void) { return 0; }
+static inline int acpi_video_register_with_quirks(void) { return 0; }
 static inline void acpi_video_unregister(void) { return; }
 static inline int acpi_video_get_edid(struct acpi_device *device, int type,
                                       int device_id, void **edid)
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index 353ba256f368..6ad72f92469c 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -191,6 +191,7 @@ extern bool wmi_has_guid(const char *guid);
 #define ACPI_VIDEO_BACKLIGHT_DMI_VIDEO                  0x0200
 #define ACPI_VIDEO_OUTPUT_SWITCHING_DMI_VENDOR          0x0400
 #define ACPI_VIDEO_OUTPUT_SWITCHING_DMI_VIDEO           0x0800
+#define ACPI_VIDEO_SKIP_BACKLIGHT                       0x1000
 
 #if defined(CONFIG_ACPI_VIDEO) || defined(CONFIG_ACPI_VIDEO_MODULE)