NFC: Stop sending LLCP frames when tx queues are getting too deep
When the tx pending queues and/or the socket tx queue is getting too deep,
we have to let userspace know. We won't be queueing any more frames until
the congestion is fixed.
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
diff --git a/net/nfc/llcp/commands.c b/net/nfc/llcp/commands.c
index f0a3945..df24be4 100644
--- a/net/nfc/llcp/commands.c
+++ b/net/nfc/llcp/commands.c
@@ -528,6 +528,23 @@
if (local == NULL)
return -ENODEV;
+ /* Remote is ready but has not acknowledged our frames */
+ if((sock->remote_ready &&
+ skb_queue_len(&sock->tx_pending_queue) >= sock->rw &&
+ skb_queue_len(&sock->tx_queue) >= 2 * sock->rw)) {
+ pr_err("Pending queue is full %d frames\n",
+ skb_queue_len(&sock->tx_pending_queue));
+ return -ENOBUFS;
+ }
+
+ /* Remote is not ready and we've been queueing enough frames */
+ if ((!sock->remote_ready &&
+ skb_queue_len(&sock->tx_queue) >= 2 * sock->rw)) {
+ pr_err("Tx queue is full %d frames\n",
+ skb_queue_len(&sock->tx_queue));
+ return -ENOBUFS;
+ }
+
msg_data = kzalloc(len, GFP_KERNEL);
if (msg_data == NULL)
return -ENOMEM;