diff --git a/drivers/misc/ti-st/st_core.c b/drivers/misc/ti-st/st_core.c
index 84d73c5..79d2dc3 100644
--- a/drivers/misc/ti-st/st_core.c
+++ b/drivers/misc/ti-st/st_core.c
@@ -65,7 +65,7 @@
 	struct tty_struct *tty;
 	if (unlikely(st_gdata == NULL || st_gdata->tty == NULL)) {
 		pr_err("tty unavailable to perform write");
-		return -1;
+		return -EINVAL;
 	}
 	tty = st_gdata->tty;
 #ifdef VERBOSE
@@ -124,9 +124,15 @@
 	pr_info(" %s ", __func__);
 	for (i = 0; i < ST_MAX_CHANNELS; i++) {
 		if (likely(st_gdata != NULL && st_gdata->list[i] != NULL &&
-			   st_gdata->list[i]->reg_complete_cb != NULL))
+			   st_gdata->list[i]->reg_complete_cb != NULL)) {
 			st_gdata->list[i]->reg_complete_cb
 				(st_gdata->list[i]->priv_data, err);
+			pr_info("protocol %d's cb sent %d\n", i, err);
+			if (err) { /* cleanup registered protocol */
+				st_gdata->protos_registered--;
+				st_gdata->list[i] = NULL;
+			}
+		}
 	}
 }
 
@@ -457,15 +463,7 @@
 	if (st_gdata == NULL || new_proto == NULL || new_proto->recv == NULL
 	    || new_proto->reg_complete_cb == NULL) {
 		pr_err("gdata/new_proto/recv or reg_complete_cb not ready");
-		if (st_gdata == NULL)
-			pr_err("error 1\n");
-		if (new_proto == NULL)
-			pr_err("error 2\n");
-		if (new_proto->recv == NULL)
-			pr_err("error 3\n");
-		if (new_proto->reg_complete_cb == NULL)
-			pr_err("erro 4\n");
-		return -1;
+		return -EINVAL;
 	}
 
 	if (new_proto->chnl_id >= ST_MAX_CHANNELS) {
@@ -512,10 +510,9 @@
 			if ((st_gdata->protos_registered != ST_EMPTY) &&
 			    (test_bit(ST_REG_PENDING, &st_gdata->st_state))) {
 				pr_err(" KIM failure complete callback ");
-				st_reg_complete(st_gdata, -1);
+				st_reg_complete(st_gdata, err);
 			}
-
-			return -1;
+			return -EINVAL;
 		}
 
 		/* the chnl_id might require other gpios to be toggled
@@ -634,14 +631,14 @@
 	if (unlikely(skb == NULL || st_gdata == NULL
 		|| st_gdata->tty == NULL)) {
 		pr_err("data/tty unavailable to perform write");
-		return -1;
+		return -EINVAL;
 	}
 #ifdef DEBUG			/* open-up skb to read the 1st byte */
 	chnl_id = skb->data[0];
 	if (unlikely(st_gdata->list[chnl_id] == NULL)) {
 		pr_err(" chnl_id %d not registered, and writing? ",
 			   chnl_id);
-		return -1;
+		return -EINVAL;
 	}
 #endif
 	pr_debug("%d to be written", skb->len);
@@ -829,7 +826,7 @@
 		err = tty_unregister_ldisc(N_TI_WL);
 		if (err)
 			pr_err("unable to un-register ldisc");
-		return -1;
+		return err;
 	}
 	*core_data = st_gdata;
 	return 0;
diff --git a/drivers/misc/ti-st/st_kim.c b/drivers/misc/ti-st/st_kim.c
index a7fda81..ccc46a7b 100644
--- a/drivers/misc/ti-st/st_kim.c
+++ b/drivers/misc/ti-st/st_kim.c
@@ -201,13 +201,13 @@
 	INIT_COMPLETION(kim_gdata->kim_rcvd);
 	if (4 != st_int_write(kim_gdata->core_data, read_ver_cmd, 4)) {
 		pr_err("kim: couldn't write 4 bytes");
-		return -1;
+		return -EIO;
 	}
 
 	if (!wait_for_completion_timeout
 	    (&kim_gdata->kim_rcvd, msecs_to_jiffies(CMD_RESP_TIME))) {
 		pr_err(" waiting for ver info- timed out ");
-		return -1;
+		return -ETIMEDOUT;
 	}
 
 	version =
@@ -257,7 +257,7 @@
 		     (kim_gdata->fw_entry->size == 0))) {
 		pr_err(" request_firmware failed(errno %ld) for %s", err,
 			   bts_scr_name);
-		return -1;
+		return -EINVAL;
 	}
 	ptr = (void *)kim_gdata->fw_entry->data;
 	len = kim_gdata->fw_entry->size;
@@ -292,7 +292,7 @@
 					   ((struct bts_action *)ptr)->size);
 			if (unlikely(err < 0)) {
 				release_firmware(kim_gdata->fw_entry);
-				return -1;
+				return err;
 			}
 			if (!wait_for_completion_timeout
 			    (&kim_gdata->kim_rcvd,
@@ -301,7 +301,7 @@
 				    (" response timeout during fw download ");
 				/* timed out */
 				release_firmware(kim_gdata->fw_entry);
-				return -1;
+				return -ETIMEDOUT;
 			}
 			break;
 		case ACTION_DELAY:	/* sleep */
@@ -436,7 +436,7 @@
 			pr_info("ldisc_install = 0");
 			sysfs_notify(&kim_gdata->kim_pdev->dev.kobj,
 					NULL, "install");
-			err = -1;
+			err = -ETIMEDOUT;
 			continue;
 		} else {
 			/* ldisc installed now */
@@ -482,7 +482,7 @@
 			msecs_to_jiffies(LDISC_TIME));
 	if (!err) {		/* timeout */
 		pr_err(" timed out waiting for ldisc to be un-installed");
-		return -1;
+		return -ETIMEDOUT;
 	}
 
 	/* By default configure BT nShutdown to LOW state */
@@ -642,7 +642,7 @@
 	status = st_core_init(&kim_gdata->core_data);
 	if (status != 0) {
 		pr_err(" ST core init failed");
-		return -1;
+		return -EIO;
 	}
 	/* refer to itself */
 	kim_gdata->core_data->kim_data = kim_gdata;
@@ -704,7 +704,7 @@
 	if (IS_ERR(kim_debugfs_dir)) {
 		pr_err(" debugfs entries creation failed ");
 		kim_debugfs_dir = NULL;
-		return -1;
+		return -EIO;
 	}
 
 	debugfs_create_file("version", S_IRUGO, kim_debugfs_dir,
diff --git a/drivers/misc/ti-st/st_ll.c b/drivers/misc/ti-st/st_ll.c
index 2bda8de..f72de6b 100644
--- a/drivers/misc/ti-st/st_ll.c
+++ b/drivers/misc/ti-st/st_ll.c
@@ -130,7 +130,7 @@
 		break;
 	default:
 		pr_err(" unknown input/state ");
-		return -1;
+		return -EINVAL;
 	}
 	return 0;
 }