3 files changed, 13 insertions, 1 deletions

diff --git a/drivers/acpi/video.c b/drivers/acpi/video.c
index fb9ffe9adc64..5bb1278e9324 100644
--- a/drivers/acpi/video.c
+++ b/drivers/acpi/video.c
@@ -241,13 +241,14 @@ static bool acpi_video_use_native_backlight(void)
                 return use_native_backlight_dmi;
 }
 
-static bool acpi_video_verify_backlight_support(void)
+bool acpi_video_verify_backlight_support(void)
 {
         if (acpi_osi_is_win8() && acpi_video_use_native_backlight() &&
             backlight_device_registered(BACKLIGHT_RAW))
                 return false;
         return acpi_video_backlight_support();
 }
+EXPORT_SYMBOL_GPL(acpi_video_verify_backlight_support);
 
 /* backlight device sysfs support */
 static int acpi_video_get_brightness(struct backlight_device *bd)
diff --git a/drivers/gpu/drm/i915/intel_opregion.c b/drivers/gpu/drm/i915/intel_opregion.c
index 2e2c71fcc9ed..4f6b53998d79 100644
--- a/drivers/gpu/drm/i915/intel_opregion.c
+++ b/drivers/gpu/drm/i915/intel_opregion.c
@@ -403,6 +403,15 @@ static u32 asle_set_backlight(struct drm_device *dev, u32 bclp)
 
         DRM_DEBUG_DRIVER("bclp = 0x%08x\n", bclp);
 
+        /*
+         * If the acpi_video interface is not supposed to be used, don't
+         * bother processing backlight level change requests from firmware.
+         */
+        if (!acpi_video_verify_backlight_support()) {
+                DRM_DEBUG_KMS("opregion backlight request ignored\n");
+                return 0;
+        }
+
         if (!(bclp & ASLE_BCLP_VALID))
                 return ASLC_BACKLIGHT_FAILED;
 
diff --git a/include/acpi/video.h b/include/acpi/video.h
index ea4c7bbded4d..843ef1adfbfa 100644
--- a/include/acpi/video.h
+++ b/include/acpi/video.h
@@ -22,6 +22,7 @@ extern void acpi_video_unregister(void);
 extern void acpi_video_unregister_backlight(void);
 extern int acpi_video_get_edid(struct acpi_device *device, int type,
                                int device_id, void **edid);
+extern bool acpi_video_verify_backlight_support(void);
 #else
 static inline int acpi_video_register(void) { return 0; }
 static inline void acpi_video_unregister(void) { return; }
@@ -31,6 +32,7 @@ static inline int acpi_video_get_edid(struct acpi_device *device, int type,
 {
         return -ENODEV;
 }
+static inline bool acpi_video_verify_backlight_support(void) { return false; }
 #endif
 
 #endif