commit 40264438e5320d4bf2cde5d8c1c2ddc4637d3042
Author: Nicolas Morey-Chaisemartin <nmoreychaisemartin@suse.com>
Date:   Tue May 29 07:53:52 2018 +0200

    ucm, mcm: fix backlog parameter for socket
    
    Using listen(, 0) forces a synchronization barrier between connect and accept
    if net.ipv4.tcp_syncookies. As this is done by a single thread, it causes connect
    to timeout with a similar message:
    open_hca: failed to init cr pipe - Connection timed out
    
    Replace with listen(, 1) so the kernel can accept the connection itself and remove
    the synchronisation point.
    
    Signed-off-by: Nicolas Morey-Chaisemartin <nmoreychaisemartin@suse.com>

diff --git dapl/openib_mcm/device.c dapl/openib_mcm/device.c
index 2e30221ac2d2..5ea25615f683 100644
--- dapl/openib_mcm/device.c
+++ dapl/openib_mcm/device.c
@@ -59,7 +59,7 @@ static int32_t create_os_signal(IN DAPL_HCA * hca_ptr)
 	if (ret)
 		goto err1;
 
-	ret = listen(listen_socket, 0);
+	ret = listen(listen_socket, 1);
 	if (ret)
 		goto err1;
 
diff --git dapl/openib_ucm/device.c dapl/openib_ucm/device.c
index 11f7334ec348..9e257835f44b 100644
--- dapl/openib_ucm/device.c
+++ dapl/openib_ucm/device.c
@@ -92,7 +92,7 @@ static int32_t create_os_signal(IN DAPL_HCA * hca_ptr)
 	if (ret)
 		goto err1;
 
-	ret = listen(listen_socket, 0);
+	ret = listen(listen_socket, 1);
 	if (ret)
 		goto err1;