From 8be9cb9f7253020232537eeec6bf4d64518b055a Mon Sep 17 00:00:00 2001
From: Alexander Lunev <alexanderlunev@mail.ru>
Date: Tue, 25 Jan 2022 19:48:26 +0300
Subject: [PATCH] net/tcp/sendfile: notify the device driver of the
 availability of TX data on TCP retransmission (as well as on sending normal
 TCP packets).

---
 net/tcp/tcp_sendfile.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/net/tcp/tcp_sendfile.c b/net/tcp/tcp_sendfile.c
index bae5d1af347..5ee6f4056da 100644
--- a/net/tcp/tcp_sendfile.c
+++ b/net/tcp/tcp_sendfile.c
@@ -307,6 +307,10 @@ static uint16_t sendfile_eventhandler(FAR struct net_driver_s *dev,
 
       dev->d_sndlen = sndlen;
 
+      /* Notify the device driver of the availability of TX data */
+
+      tcp_send_txnotify(psock, conn);
+
       /* Continue waiting */
 
       return flags;