diff --git a/drivers/gpu/drm/drm_fourcc.c b/drivers/gpu/drm/drm_fourcc.c
index 23d4b82ec17c..523ed916a1c0 100644
--- a/drivers/gpu/drm/drm_fourcc.c
+++ b/drivers/gpu/drm/drm_fourcc.c
@@ -102,15 +102,11 @@ char *drm_get_format_name(uint32_t format)
 }
 EXPORT_SYMBOL(drm_get_format_name);
 
-/**
- * drm_format_info - query information for a given format
- * @format: pixel format (DRM_FORMAT_*)
- *
- * Returns:
- * The instance of struct drm_format_info that describes the pixel format, or
- * NULL if the format is unsupported.
+/*
+ * Internal function to query information for a given format. See
+ * drm_format_info() for the public API.
  */
-const struct drm_format_info *drm_format_info(u32 format)
+const struct drm_format_info *__drm_format_info(u32 format)
 {
 	static const struct drm_format_info formats[] = {
 		{ .format = DRM_FORMAT_C8,		.depth = 8,  .num_planes = 1, .cpp = { 1, 0, 0 }, .hsub = 1, .vsub = 1 },
@@ -184,6 +180,26 @@ const struct drm_format_info *drm_format_info(u32 format)
 
 	return NULL;
 }
+
+/**
+ * drm_format_info - query information for a given format
+ * @format: pixel format (DRM_FORMAT_*)
+ *
+ * The caller should only pass a supported pixel format to this function.
+ * Unsupported pixel formats will generate a warning in the kernel log.
+ *
+ * Returns:
+ * The instance of struct drm_format_info that describes the pixel format, or
+ * NULL if the format is unsupported.
+ */
+const struct drm_format_info *drm_format_info(u32 format)
+{
+	const struct drm_format_info *info;
+
+	info = __drm_format_info(format);
+	WARN_ON(!info);
+	return info;
+}
 EXPORT_SYMBOL(drm_format_info);
 
 /**
diff --git a/drivers/gpu/drm/drm_framebuffer.c b/drivers/gpu/drm/drm_framebuffer.c
index 386977df72ce..49fd7db758e0 100644
--- a/drivers/gpu/drm/drm_framebuffer.c
+++ b/drivers/gpu/drm/drm_framebuffer.c
@@ -131,7 +131,7 @@ static int framebuffer_check(const struct drm_mode_fb_cmd2 *r)
 	const struct drm_format_info *info;
 	int i;
 
-	info = drm_format_info(r->pixel_format & ~DRM_FORMAT_BIG_ENDIAN);
+	info = __drm_format_info(r->pixel_format & ~DRM_FORMAT_BIG_ENDIAN);
 	if (!info) {
 		char *format_name = drm_get_format_name(r->pixel_format);
 		DRM_DEBUG_KMS("bad framebuffer format %s\n", format_name);
diff --git a/include/drm/drm_fourcc.h b/include/drm/drm_fourcc.h
index 135fef050ee6..f73f97afd1e2 100644
--- a/include/drm/drm_fourcc.h
+++ b/include/drm/drm_fourcc.h
@@ -45,6 +45,7 @@ struct drm_format_info {
 	u8 vsub;
 };
 
+const struct drm_format_info *__drm_format_info(u32 format);
 const struct drm_format_info *drm_format_info(u32 format);
 uint32_t drm_mode_legacy_fb_format(uint32_t bpp, uint32_t depth);
 void drm_fb_get_bpp_depth(uint32_t format, unsigned int *depth, int *bpp);