Bluetooth: handle priority change within quote

The quote is calculated based on the first buffer in the queue so if the
priority changes to something lower than the priority of the first skb
the quote needs to be recalculated.
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>

net/bluetooth/hci_core.c

@@ -2193,10 +2193,17 @@ static inline void hci_sched_acl(struct hci_dev *hdev)
 
 	while (hdev->acl_cnt &&
 			(chan = hci_chan_sent(hdev, ACL_LINK, &quote))) {
-		while (quote-- && (skb = skb_dequeue(&chan->data_q))) {
+		u32 priority = (skb_peek(&chan->data_q))->priority;
+		while (quote-- && (skb = skb_peek(&chan->data_q))) {
 			BT_DBG("chan %p skb %p len %d priority %u", chan, skb,
 					skb->len, skb->priority);
 
+			/* Stop if priority has changed */
+			if (skb->priority < priority)
+				break;
+
+			skb = skb_dequeue(&chan->data_q);
+
 			hci_conn_enter_active_mode(chan->conn,
 						bt_cb(skb)->force_active);
 
@@ -2278,10 +2285,17 @@ static inline void hci_sched_le(struct hci_dev *hdev)
 
 	cnt = hdev->le_pkts ? hdev->le_cnt : hdev->acl_cnt;
 	while (cnt && (chan = hci_chan_sent(hdev, LE_LINK, &quote))) {
-		while (quote-- && (skb = skb_dequeue(&chan->data_q))) {
+		u32 priority = (skb_peek(&chan->data_q))->priority;
+		while (quote-- && (skb = skb_peek(&chan->data_q))) {
 			BT_DBG("chan %p skb %p len %d priority %u", chan, skb,
 					skb->len, skb->priority);
 
+			/* Stop if priority has changed */
+			if (skb->priority < priority)
+				break;
+
+			skb = skb_dequeue(&chan->data_q);
+
 			hci_send_frame(skb);
 			hdev->le_last_tx = jiffies;