Index: head/sys/dev/sound/pci/hda/hdaa_patches.c
===================================================================
--- head/sys/dev/sound/pci/hda/hdaa_patches.c
+++ head/sys/dev/sound/pci/hda/hdaa_patches.c
@@ -425,12 +425,21 @@
 	} else if (id == HDA_CODEC_ALC298 && subid == DELL_XPS9560_SUBVENDOR) {
 		switch (nid) {
 		case 24:
-			config  = 0x01a1913c;
+			config = 0x01a1913c;
 			break;
 		case 26:
-			config  = 0x01a1913d;
+			config = 0x01a1913d;
 			break;
 		}
+	} else if (id == HDA_CODEC_ALC256 && subid == DELL_I7577_SUBVENDOR ) {
+		switch (nid) {
+		case 20:
+			patch = "as=1 seq=0";
+			break;
+		case 33:
+			patch = "as=1 seq=15";
+			break;
+		}
 	}
 
 	if (patch != NULL)
@@ -768,6 +777,10 @@
 			hdaa_write_coef(dev, 0x20, 0x07, 0x7cb);
 		}
 		break;
+	}
+	if (id == HDA_CODEC_ALC255 || id == HDA_CODEC_ALC256) {
+		val = hdaa_read_coef(dev, 0x20, 0x46);
+		hdaa_write_coef(dev, 0x20, 0x46, val|0x3000);
 	}
 	if (subid == APPLE_INTEL_MAC)
 		hda_command(dev, HDA_CMD_12BIT(0, devinfo->nid,
Index: head/sys/dev/sound/pci/hda/hdac.h
===================================================================
--- head/sys/dev/sound/pci/hda/hdac.h
+++ head/sys/dev/sound/pci/hda/hdac.h
@@ -203,6 +203,7 @@
 #define DELL_XPSM1210_SUBVENDOR	HDA_MODEL_CONSTRUCT(DELL, 0x01d7)
 #define DELL_OPLX745_SUBVENDOR	HDA_MODEL_CONSTRUCT(DELL, 0x01da)
 #define DELL_XPS9560_SUBVENDOR	HDA_MODEL_CONSTRUCT(DELL, 0x07be)
+#define DELL_I7577_SUBVENDOR	HDA_MODEL_CONSTRUCT(DELL, 0x0802)
 #define DELL_ALL_SUBVENDOR	HDA_MODEL_CONSTRUCT(DELL, 0xffff)
 
 /* Clevo */