From dd2bf43ffcf0d1bba94d20abc6cc44ed294db66b Mon Sep 17 00:00:00 2001 From: Samuel Ortiz Date: Thu, 1 Nov 2012 23:33:00 +0100 Subject: [PATCH] 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 --- net/nfc/llcp/commands.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/net/nfc/llcp/commands.c b/net/nfc/llcp/commands.c index f0a39456f26b..df24be48d4da 100644 --- a/net/nfc/llcp/commands.c +++ b/net/nfc/llcp/commands.c @@ -528,6 +528,23 @@ int nfc_llcp_send_i_frame(struct nfc_llcp_sock *sock, 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; -- 2.20.1