1 files changed, 53 insertions, 27 deletions

diff --git a/drivers/acpi/video.c b/drivers/acpi/video.c
index 60ea984c84a0..94b1a4c5abab 100644
--- a/drivers/acpi/video.c
+++ b/drivers/acpi/video.c
@@ -40,10 +40,12 @@
 #include <linux/pci.h>
 #include <linux/pci_ids.h>
 #include <asm/uaccess.h>
-
+#include <linux/dmi.h>
 #include <acpi/acpi_bus.h>
 #include <acpi/acpi_drivers.h>
 
+#define PREFIX "ACPI: "
+
 #define ACPI_VIDEO_CLASS                "video"
 #define ACPI_VIDEO_BUS_NAME             "Video Bus"
 #define ACPI_VIDEO_DEVICE_NAME          "Video Device"
@@ -198,7 +200,7 @@ struct acpi_video_device {
         struct acpi_device *dev;
         struct acpi_video_device_brightness *brightness;
         struct backlight_device *backlight;
-        struct thermal_cooling_device *cdev;
+        struct thermal_cooling_device *cooling_dev;
         struct output_device *output_dev;
 };
 
@@ -387,20 +389,20 @@ static struct output_properties acpi_output_properties = {
 
 
 /* thermal cooling device callbacks */
-static int video_get_max_state(struct thermal_cooling_device *cdev, unsigned
+static int video_get_max_state(struct thermal_cooling_device *cooling_dev, unsigned
                                long *state)
 {
-        struct acpi_device *device = cdev->devdata;
+        struct acpi_device *device = cooling_dev->devdata;
         struct acpi_video_device *video = acpi_driver_data(device);
 
         *state = video->brightness->count - 3;
         return 0;
 }
 
-static int video_get_cur_state(struct thermal_cooling_device *cdev, unsigned
+static int video_get_cur_state(struct thermal_cooling_device *cooling_dev, unsigned
                                long *state)
 {
-        struct acpi_device *device = cdev->devdata;
+        struct acpi_device *device = cooling_dev->devdata;
         struct acpi_video_device *video = acpi_driver_data(device);
         unsigned long long level;
         int offset;
@@ -417,9 +419,9 @@ static int video_get_cur_state(struct thermal_cooling_device *cdev, unsigned
 }
 
 static int
-video_set_cur_state(struct thermal_cooling_device *cdev, unsigned long state)
+video_set_cur_state(struct thermal_cooling_device *cooling_dev, unsigned long state)
 {
-        struct acpi_device *device = cdev->devdata;
+        struct acpi_device *device = cooling_dev->devdata;
         struct acpi_video_device *video = acpi_driver_data(device);
         int level;
 
@@ -603,6 +605,7 @@ acpi_video_device_lcd_get_level_current(struct acpi_video_device *device,
                                         unsigned long long *level)
 {
         acpi_status status = AE_OK;
+        int i;
 
         if (device->cap._BQC || device->cap._BCQ) {
                 char *buf = device->cap._BQC ? "_BQC" : "_BCQ";
@@ -618,8 +621,15 @@ acpi_video_device_lcd_get_level_current(struct acpi_video_device *device,
 
                         }
                         *level += bqc_offset_aml_bug_workaround;
-                        device->brightness->curr = *level;
-                        return 0;
+                        for (i = 2; i < device->brightness->count; i++)
+                                if (device->brightness->levels[i] == *level) {
+                                        device->brightness->curr = *level;
+                                        return 0;
+                        }
+                        /* BQC returned an invalid level. Stop using it.  */
+                        ACPI_WARNING((AE_INFO, "%s returned an invalid level",
+                                                buf));
+                        device->cap._BQC = device->cap._BCQ = 0;
                 } else {
                         /* Fixme:
                          * should we return an error or ignore this failure?
@@ -870,7 +880,7 @@ acpi_video_init_brightness(struct acpi_video_device *device)
         br->flags._BCM_use_index = br->flags._BCL_use_index;
 
         /* _BQC uses INDEX while _BCL uses VALUE in some laptops */
-        br->curr = level_old = max_level;
+        br->curr = level = max_level;
 
         if (!device->cap._BQC)
                 goto set_level;
@@ -892,15 +902,25 @@ acpi_video_init_brightness(struct acpi_video_device *device)
 
         br->flags._BQC_use_index = (level == max_level ? 0 : 1);
 
-        if (!br->flags._BQC_use_index)
+        if (!br->flags._BQC_use_index) {
+                /*
+                 * Set the backlight to the initial state.
+                 * On some buggy laptops, _BQC returns an uninitialized value
+                 * when invoked for the first time, i.e. level_old is invalid.
+                 * set the backlight to max_level in this case
+                 */
+                for (i = 2; i < br->count; i++)
+                        if (level_old == br->levels[i])
+                                level = level_old;
                 goto set_level;
+        }
 
         if (br->flags._BCL_reversed)
                 level_old = (br->count - 1) - level_old;
-        level_old = br->levels[level_old];
+        level = br->levels[level_old];
 
 set_level:
-        result = acpi_video_device_lcd_set_level(device, level_old);
+        result = acpi_video_device_lcd_set_level(device, level);
         if (result)
                 goto out_free_levels;
 
@@ -934,9 +954,6 @@ static void acpi_video_device_find_cap(struct acpi_video_device *device)
 {
         acpi_handle h_dummy1;
 
-
-        memset(&device->cap, 0, sizeof(device->cap));
-
         if (ACPI_SUCCESS(acpi_get_handle(device->dev->handle, "_ADR", &h_dummy1))) {
                 device->cap._ADR = 1;
         }
@@ -990,19 +1007,29 @@ static void acpi_video_device_find_cap(struct acpi_video_device *device)
                 if (result)
                         printk(KERN_ERR PREFIX "Create sysfs link\n");
 
-                device->cdev = thermal_cooling_device_register("LCD",
+                device->cooling_dev = thermal_cooling_device_register("LCD",
                                         device->dev, &video_cooling_ops);
-                if (IS_ERR(device->cdev))
+                if (IS_ERR(device->cooling_dev)) {
+                        /*
+                         * Set cooling_dev to NULL so we don't crash trying to
+                         * free it.
+                         * Also, why the hell we are returning early and
+                         * not attempt to register video output if cooling
+                         * device registration failed?
+                         * -- dtor
+                         */
+                        device->cooling_dev = NULL;
                         return;
+                }
 
                 dev_info(&device->dev->dev, "registered as cooling_device%d\n",
-                         device->cdev->id);
+                         device->cooling_dev->id);
                 result = sysfs_create_link(&device->dev->dev.kobj,
-                                &device->cdev->device.kobj,
+                                &device->cooling_dev->device.kobj,
                                 "thermal_cooling");
                 if (result)
                         printk(KERN_ERR PREFIX "Create sysfs link\n");
-                result = sysfs_create_link(&device->cdev->device.kobj,
+                result = sysfs_create_link(&device->cooling_dev->device.kobj,
                                 &device->dev->dev.kobj, "device");
                 if (result)
                         printk(KERN_ERR PREFIX "Create sysfs link\n");
@@ -1039,7 +1066,6 @@ static void acpi_video_bus_find_cap(struct acpi_video_bus *video)
 {
         acpi_handle h_dummy1;
 
-        memset(&video->cap, 0, sizeof(video->cap));
         if (ACPI_SUCCESS(acpi_get_handle(video->device->handle, "_DOS", &h_dummy1))) {
                 video->cap._DOS = 1;
         }
@@ -2009,13 +2035,13 @@ static int acpi_video_bus_put_one_device(struct acpi_video_device *device)
                 backlight_device_unregister(device->backlight);
                 device->backlight = NULL;
         }
-        if (device->cdev) {
+        if (device->cooling_dev) {
                 sysfs_remove_link(&device->dev->dev.kobj,
                                   "thermal_cooling");
-                sysfs_remove_link(&device->cdev->device.kobj,
+                sysfs_remove_link(&device->cooling_dev->device.kobj,
                                   "device");
-                thermal_cooling_device_unregister(device->cdev);
-                device->cdev = NULL;
+                thermal_cooling_device_unregister(device->cooling_dev);
+                device->cooling_dev = NULL;
         }
         video_output_unregister(device->output_dev);