media: cec-notifier: rename variables, check kstrdup and n->conn_name

dev -> hdmi_dev
conn -> conn_name

Check if n->conn_name is not NULL before calling strcmp.
Check the result of kstrdup, and clean up on error.
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

drivers/media/cec/cec-notifier.c

@@ -21,8 +21,8 @@ struct cec_notifier {
 	struct mutex lock;
 	struct list_head head;
 	struct kref kref;
-	struct device *dev;
-	const char *conn;
+	struct device *hdmi_dev;
+	const char *conn_name;
 	struct cec_adapter *cec_adap;
 	void (*callback)(struct cec_adapter *adap, u16 pa);
 
@@ -32,14 +32,16 @@ struct cec_notifier {
 static LIST_HEAD(cec_notifiers);
 static DEFINE_MUTEX(cec_notifiers_lock);
 
-struct cec_notifier *cec_notifier_get_conn(struct device *dev, const char *conn)
+struct cec_notifier *
+cec_notifier_get_conn(struct device *hdmi_dev, const char *conn_name)
 {
 	struct cec_notifier *n;
 
 	mutex_lock(&cec_notifiers_lock);
 	list_for_each_entry(n, &cec_notifiers, head) {
-		if (n->dev == dev &&
-		    (!conn || !strcmp(n->conn, conn))) {
+		if (n->hdmi_dev == hdmi_dev &&
+		    (!conn_name ||
+		     (n->conn_name && !strcmp(n->conn_name, conn_name)))) {
 			kref_get(&n->kref);
 			mutex_unlock(&cec_notifiers_lock);
 			return n;
@@ -48,10 +50,17 @@ struct cec_notifier *cec_notifier_get_conn(struct device *dev, const char *conn)
 	n = kzalloc(sizeof(*n), GFP_KERNEL);
 	if (!n)
 		goto unlock;
-	n->dev = dev;
-	if (conn)
-		n->conn = kstrdup(conn, GFP_KERNEL);
+	n->hdmi_dev = hdmi_dev;
+	if (conn_name) {
+		n->conn_name = kstrdup(conn_name, GFP_KERNEL);
+		if (!n->conn_name) {
+			kfree(n);
+			n = NULL;
+			goto unlock;
+		}
+	}
 	n->phys_addr = CEC_PHYS_ADDR_INVALID;
+
 	mutex_init(&n->lock);
 	kref_init(&n->kref);
 	list_add_tail(&n->head, &cec_notifiers);
@@ -67,7 +76,7 @@ static void cec_notifier_release(struct kref *kref)
 		container_of(kref, struct cec_notifier, kref);
 
 	list_del(&n->head);
-	kfree(n->conn);
+	kfree(n->conn_name);
 	kfree(n);
 }