[PATCH v2] rdma: Modify rdma_conn_param.rnr_retry to 7

"zhengbing.huang" <[email protected]> Tue, 8 Jul 2025 15:37:17 +0800
Newsgroups dev.linux.lists.drbd-dev
Message-ID <[email protected]>
During the sync process, we found that the
IB_WC_RNR_RETRY_EXC_ERR error always occurred, and then
the connection break. Then when the connection is restored,
this error occurs again, enter a loop.

When the IB_WC_RNR_RETRY_EXC_ERR error occurs,
it indicates that there is no rx_desc at the receive side currently.
Then we query that the current rnr_retry value is 0,
meane there is no retry.

So we modify rnr_retry to 7(max value), and the problem did not occur again.

Signed-off-by: zhengbing.huang <[email protected]>
---
 drbd/drbd_transport_rdma.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drbd/drbd_transport_rdma.c b/drbd/drbd_transport_rdma.c
index 30edfaf96..14392a33b 100644
--- a/drbd/drbd_transport_rdma.c
+++ b/drbd/drbd_transport_rdma.c
@@ -409,6 +409,7 @@ static struct rdma_conn_param dtr_conn_param = {
 	.responder_resources = 1,
 	.initiator_depth = 1,
 	.retry_count = 10,
+	.rnr_retry_count  = 7,
 };
 
 static u32 dtr_cm_to_lkey(struct dtr_cm *cm)
-- 
2.43.0