From e7cf1b761d2e268b2ae79a70885789912d58005f Mon Sep 17 00:00:00 2001
From: Yossi Itigin <yosefe@mellanox.com>
Date: Tue, 11 Jun 2019 12:40:24 +0000
Subject: [PATCH] UCT/IB: Fallback to ibv_create_cq() if ibv_create_cq_ex()
 returns ENOSYS

---
 NEWS                       | 1 +
 src/uct/ib/base/ib_iface.c | 9 ++++++---
 2 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/NEWS b/NEWS
index e7e2a58e13f..90dc718e159 100644
--- a/NEWS
+++ b/NEWS
@@ -27,6 +27,7 @@ Bugfixes:
 - Fixing the wrong name of aliases
 - Fix data race in UCP wireup
 - Fix segfault when libuct.so is reloaded - issue #3558
+- Fallback to ibv_create_cq() if ibv_create_cq_ex() returns ENOSYS
 
 Tested configurations:
 - RDMA: MLNX_OFED 4.5, distribution inbox drivers, rdma-core 22.1
diff --git a/src/uct/ib/base/ib_iface.c b/src/uct/ib/base/ib_iface.c
index 1be435a06a6..707197636b2 100644
--- a/src/uct/ib/base/ib_iface.c
+++ b/src/uct/ib/base/ib_iface.c
@@ -588,16 +588,19 @@ ucs_status_t uct_ib_verbs_create_cq(struct ibv_context *context, int cqe,
     }
 
     cq = ibv_cq_ex_to_cq(ibv_create_cq_ex(context, &cq_attr));
-#else
-    cq = ibv_create_cq(context, cqe, NULL, channel, comp_vector);
+    if (!cq && (errno == ENOSYS))
 #endif
+    {
+        *inl = 0;
+        cq = ibv_create_cq(context, cqe, NULL, channel, comp_vector);
+    }
+
     if (!cq) {
         ucs_error("ibv_create_cq(cqe=%d) failed: %m", cqe);
         return UCS_ERR_IO_ERROR;
     }
 
     *cq_p = cq;
-    *inl  = 0;
     return UCS_OK;
 }