From 1175f0cf29acbb8328e1ab054bb0f5d7077c3cc0 Mon Sep 17 00:00:00 2001
From: Michael Brown
Date: Mon, 10 Aug 2009 02:10:17 +0100
Subject: [hermon] Reduce the RC ACK timeout

The ACK timeout determines how long we take to notice a failed
Reliable Connection.  Reducing it from the arbitrary value of 19 down
to 14 reduces the individual ACK timeout from around 2.1s to 67ms;
this in turn reduces the time to tear down and re-establish a broken
SRP session from around 30s to around 1s.
---
 src/drivers/infiniband/hermon.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/drivers/infiniband/hermon.c b/src/drivers/infiniband/hermon.c
index 0012904f..bff128fd 100644
--- a/src/drivers/infiniband/hermon.c
+++ b/src/drivers/infiniband/hermon.c
@@ -1108,7 +1108,7 @@ static int hermon_modify_qp ( struct ib_device *ibdev,
 		memset ( &qpctx, 0, sizeof ( qpctx ) );
 		MLX_FILL_1 ( &qpctx, 10,
 			     qpc_eec_data.primary_address_path.ack_timeout,
-			     0x13 );
+			     14 /* 4.096us * 2^(14) = 67ms */ );
 		MLX_FILL_2 ( &qpctx, 30,
 			     qpc_eec_data.retry_count, HERMON_RETRY_MAX,
 			     qpc_eec_data.rnr_retry, HERMON_RETRY_MAX );
-- 
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