drm/edid: add drm_edid_duplicate

We have some code duplication related to EDID duplication. Add a helper.
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>

drivers/gpu/drm/drm_edid.c

@@ -1264,6 +1264,18 @@ struct edid *drm_get_edid(struct drm_connector *connector,
 }
 EXPORT_SYMBOL(drm_get_edid);
 
+/**
+ * drm_edid_duplicate - duplicate an EDID and the extensions
+ * @edid: EDID to duplicate
+ *
+ * Return duplicate edid or NULL on allocation failure.
+ */
+struct edid *drm_edid_duplicate(const struct edid *edid)
+{
+	return kmemdup(edid, (edid->extensions + 1) * EDID_LENGTH, GFP_KERNEL);
+}
+EXPORT_SYMBOL(drm_edid_duplicate);
+
 /*** EDID parsing ***/
 
 /**

include/drm/drm_crtc.h

@@ -964,6 +964,7 @@ extern int drm_mode_group_init_legacy_group(struct drm_device *dev, struct drm_m
 extern bool drm_probe_ddc(struct i2c_adapter *adapter);
 extern struct edid *drm_get_edid(struct drm_connector *connector,
 				 struct i2c_adapter *adapter);
+extern struct edid *drm_edid_duplicate(const struct edid *edid);
 extern int drm_add_edid_modes(struct drm_connector *connector, struct edid *edid);
 extern void drm_mode_probed_add(struct drm_connector *connector, struct drm_display_mode *mode);
 extern void drm_mode_copy(struct drm_display_mode *dst, const struct drm_display_mode *src);