Bluetooth: make use of connection number to optimize the scheduler

This checks if there is any existing connection according to its type
before start iterating in the list and immediately stop iterating when
reaching the number of connections.
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>

include/net/bluetooth/hci_core.h

@@ -395,6 +395,22 @@ static inline void hci_conn_hash_del(struct hci_dev *hdev, struct hci_conn *c)
 	}
 }
 
+static inline unsigned int hci_conn_num(struct hci_dev *hdev, __u8 type)
+{
+	struct hci_conn_hash *h = &hdev->conn_hash;
+	switch (type) {
+	case ACL_LINK:
+		return h->acl_num;
+	case LE_LINK:
+		return h->le_num;
+	case SCO_LINK:
+	case ESCO_LINK:
+		return h->sco_num;
+	default:
+		return 0;
+	}
+}
+
 static inline struct hci_conn *hci_conn_hash_lookup_handle(struct hci_dev *hdev,
 								__u16 handle)
 {

net/bluetooth/hci_core.c

@@ -2074,6 +2074,9 @@ static inline struct hci_conn *hci_low_sent(struct hci_dev *hdev, __u8 type, int
 			min  = c->sent;
 			conn = c;
 		}
+
+		if (hci_conn_num(hdev, type) == num)
+			break;
 	}
 
 	if (conn) {
@@ -2131,6 +2134,9 @@ static inline void hci_sched_acl(struct hci_dev *hdev)
 
 	BT_DBG("%s", hdev->name);
 
+	if (!hci_conn_num(hdev, ACL_LINK))
+		return;
+
 	if (!test_bit(HCI_RAW, &hdev->flags)) {
 		/* ACL tx timeout must be longer than maximum
 		 * link supervision timeout (40.9 seconds) */
@@ -2162,6 +2168,9 @@ static inline void hci_sched_sco(struct hci_dev *hdev)
 
 	BT_DBG("%s", hdev->name);
 
+	if (!hci_conn_num(hdev, SCO_LINK))
+		return;
+
 	while (hdev->sco_cnt && (conn = hci_low_sent(hdev, SCO_LINK, &quote))) {
 		while (quote-- && (skb = skb_dequeue(&conn->data_q))) {
 			BT_DBG("skb %p len %d", skb, skb->len);
@@ -2182,6 +2191,9 @@ static inline void hci_sched_esco(struct hci_dev *hdev)
 
 	BT_DBG("%s", hdev->name);
 
+	if (!hci_conn_num(hdev, ESCO_LINK))
+		return;
+
 	while (hdev->sco_cnt && (conn = hci_low_sent(hdev, ESCO_LINK, &quote))) {
 		while (quote-- && (skb = skb_dequeue(&conn->data_q))) {
 			BT_DBG("skb %p len %d", skb, skb->len);
@@ -2202,6 +2214,9 @@ static inline void hci_sched_le(struct hci_dev *hdev)
 
 	BT_DBG("%s", hdev->name);
 
+	if (!hci_conn_num(hdev, LE_LINK))
+		return;
+
 	if (!test_bit(HCI_RAW, &hdev->flags)) {
 		/* LE tx timeout must be longer than maximum
 		 * link supervision timeout (40.9 seconds) */