diff --git a/drivers/acpi/acpi_video.c b/drivers/acpi/acpi_video.c
index d1e41f30c004..a7c3d11e0dac 100644
--- a/drivers/acpi/acpi_video.c
+++ b/drivers/acpi/acpi_video.c
@@ -2296,16 +2296,6 @@ void acpi_video_register_backlight(void)
 }
 EXPORT_SYMBOL(acpi_video_register_backlight);
 
-void acpi_video_unregister_backlight(void)
-{
-	struct acpi_video_bus *video;
-
-	mutex_lock(&video_list_lock);
-	list_for_each_entry(video, &video_bus_head, entry)
-		acpi_video_bus_unregister_backlight(video);
-	mutex_unlock(&video_list_lock);
-}
-
 bool acpi_video_handles_brightness_key_presses(void)
 {
 	return may_report_brightness_keys &&
diff --git a/drivers/acpi/video_detect.c b/drivers/acpi/video_detect.c
index 3861d4121172..67a0211c07b4 100644
--- a/drivers/acpi/video_detect.c
+++ b/drivers/acpi/video_detect.c
@@ -38,8 +38,6 @@
 #include <linux/workqueue.h>
 #include <acpi/video.h>
 
-void acpi_video_unregister_backlight(void);
-
 static enum acpi_backlight_type acpi_backlight_cmdline = acpi_backlight_undef;
 static enum acpi_backlight_type acpi_backlight_dmi = acpi_backlight_undef;
 
@@ -817,17 +815,3 @@ bool acpi_video_backlight_use_native(void)
 	return __acpi_video_get_backlight_type(true) == acpi_backlight_native;
 }
 EXPORT_SYMBOL(acpi_video_backlight_use_native);
-
-/*
- * Set the preferred backlight interface type based on DMI info.
- * This function allows DMI blacklists to be implemented by external
- * platform drivers instead of putting a big blacklist in video_detect.c
- */
-void acpi_video_set_dmi_backlight_type(enum acpi_backlight_type type)
-{
-	acpi_backlight_dmi = type;
-	/* Remove acpi-video backlight interface if it is no longer desired */
-	if (acpi_video_get_backlight_type() != acpi_backlight_video)
-		acpi_video_unregister_backlight();
-}
-EXPORT_SYMBOL(acpi_video_set_dmi_backlight_type);
diff --git a/include/acpi/video.h b/include/acpi/video.h
index dbd48cb8bd23..a275c35e5249 100644
--- a/include/acpi/video.h
+++ b/include/acpi/video.h
@@ -60,7 +60,6 @@ extern int acpi_video_get_edid(struct acpi_device *device, int type,
 			       int device_id, void **edid);
 extern enum acpi_backlight_type acpi_video_get_backlight_type(void);
 extern bool acpi_video_backlight_use_native(void);
-extern void acpi_video_set_dmi_backlight_type(enum acpi_backlight_type type);
 /*
  * Note: The value returned by acpi_video_handles_brightness_key_presses()
  * may change over time and should not be cached.
@@ -86,9 +85,6 @@ static inline bool acpi_video_backlight_use_native(void)
 {
 	return true;
 }
-static inline void acpi_video_set_dmi_backlight_type(enum acpi_backlight_type type)
-{
-}
 static inline bool acpi_video_handles_brightness_key_presses(void)
 {
 	return false;