Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

[cascardo/linux.git] / drivers / acpi / video.c

diff --git a/drivers/acpi/video.c b/drivers/acpi/video.c
index 3bd1eaa..18dbdff 100644 (file)
--- a/drivers/acpi/video.c
+++ b/drivers/acpi/video.c
@@ -88,6 +88,13 @@ module_param(allow_duplicates, bool, 0644);
 static bool use_bios_initial_backlight = 1;
 module_param(use_bios_initial_backlight, bool, 0644);
 
+/*
+ * For Windows 8 systems: if set ture and the GPU driver has
+ * registered a backlight interface, skip registering ACPI video's.
+ */
+static bool use_native_backlight = false;
+module_param(use_native_backlight, bool, 0644);
+
 static int register_count;
 static struct mutex video_list_lock;
 static struct list_head video_bus_head;
@@ -232,6 +239,14 @@ static int acpi_video_get_next_level(struct acpi_video_device *device,
 static int acpi_video_switch_brightness(struct acpi_video_device *device,
                                         int event);
 
+static bool acpi_video_verify_backlight_support(void)
+{
+       if (acpi_osi_is_win8() && use_native_backlight &&
+           backlight_device_registered(BACKLIGHT_RAW))
+               return false;
+       return acpi_video_backlight_support();
+}
+
 /* backlight device sysfs support */
 static int acpi_video_get_brightness(struct backlight_device *bd)
 {
@@ -833,9 +848,9 @@ acpi_video_init_brightness(struct acpi_video_device *device)
                 * or an index). Set the backlight to max_level in this case.
                 */
                for (i = 2; i < br->count; i++)
-                       if (level_old == br->levels[i])
+                       if (level == br->levels[i])
                                break;
-               if (i == br->count)
+               if (i == br->count || !level)
                        level = max_level;
        }
 
@@ -1256,8 +1271,8 @@ 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)
@@ -1386,13 +1401,13 @@ acpi_video_bus_get_devices(struct acpi_video_bus *video,
 static int acpi_video_bus_start_devices(struct acpi_video_bus *video)
 {
        return acpi_video_bus_DOS(video, 0,
-                                 acpi_video_backlight_quirks() ? 1 : 0);
+                                 acpi_osi_is_win8() ? 1 : 0);
 }
 
 static int acpi_video_bus_stop_devices(struct acpi_video_bus *video)
 {
        return acpi_video_bus_DOS(video, 0,
-                                 acpi_video_backlight_quirks() ? 0 : 1);
+                                 acpi_osi_is_win8() ? 0 : 1);
 }
 
 static void acpi_video_bus_notify(struct acpi_device *device, u32 event)
@@ -1558,7 +1573,7 @@ acpi_video_bus_match(acpi_handle handle, u32 level, void *context,
 
 static void acpi_video_dev_register_backlight(struct acpi_video_device *device)
 {
-       if (acpi_video_backlight_support()) {
+       if (acpi_video_verify_backlight_support()) {
                struct backlight_properties props;
                struct pci_dev *pdev;
                acpi_handle acpi_parent;