--- hdaa_patches.c.org	2017-12-07 22:11:05.806670000 +0900
+++ hdaa_patches.c	2017-12-11 13:56:47.993850000 +0900
@@ -769,4 +769,8 @@
 			hdaa_write_coef(dev, 0x20, 0x12, 0x2800);
 		}
 	}
+	if (id == HDA_CODEC_ALC256) {
+		val = hdaa_read_coef(dev, 0x20, 0x46);
+		hdaa_write_coef(dev, 0x20, 0x46, val|0x3000);
+	}
 }