[3.16.y-ckt stable] Patch "IB/core: Use GRH when the path hop-limit > 0" has been added to the 3.16.y-ckt tree

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    IB/core: Use GRH when the path hop-limit > 0

to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.16.y-queue

This patch is scheduled to be released in version 3.16.7-ckt26.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.16.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

---8<------------------------------------------------------------

>From 8e003871c4eefdf21ff930f49344b4f6c9fb5edd Mon Sep 17 00:00:00 2001
From: Or Gerlitz <ogerlitz at mellanox.com>
Date: Tue, 1 Mar 2016 18:52:23 +0200
Subject: IB/core: Use GRH when the path hop-limit > 0

commit 11d8d645343efba0c975aefe7c2cf3b33c836c75 upstream.

According to IBTA spec v1.3 section 12.7.19, QPs should use GRH when
the path returned by the SA has hop-limit > 0. Currently, we do that
only for the > 1 case, fix that.

Fixes: 6d969a471ba1 ('IB/sa: Add ib_init_ah_from_path()')
Signed-off-by: Or Gerlitz <ogerlitz at mellanox.com>
Reviewed-by: Jason Gunthorpe <jgunthorpe at obsidianresearch.com>
Signed-off-by: Doug Ledford <dledford at redhat.com>
[ luis: backported to 3.16: adjusted context ]
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/infiniband/core/sa_query.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/infiniband/core/sa_query.c b/drivers/infiniband/core/sa_query.c
index 233eaf541f55..3ca38f9ad26a 100644
--- a/drivers/infiniband/core/sa_query.c
+++ b/drivers/infiniband/core/sa_query.c
@@ -542,7 +542,7 @@ int ib_init_ah_from_path(struct ib_device *device, u8 port_num,

 	force_grh = rdma_port_get_link_layer(device, port_num) == IB_LINK_LAYER_ETHERNET;

-	if (rec->hop_limit > 1 || force_grh) {
+	if (rec->hop_limit > 0 || force_grh) {
 		ah_attr->ah_flags = IB_AH_GRH;
 		ah_attr->grh.dgid = rec->dgid;