From: Michael Brown <mcb30@etherboot.org>
Date: Mon, 10 Aug 2009 01:10:17 +0000 (+0100)
Subject: [hermon] Reduce the RC ACK timeout
X-Git-Tag: v0.9.8~22
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=1175f0cf29acbb8328e1ab054bb0f5d7077c3cc0;p=thirdparty%2Fipxe.git

[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.
---

diff --git a/src/drivers/infiniband/hermon.c b/src/drivers/infiniband/hermon.c
index 0012904f8..bff128fd0 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 );