IB/mad: Handle DR SMPs with a LID routed part

Fix handling of directed route SMPs with a beginning or ending LID
routed part.

Signed-off-by: Ralph Campbell <ralphc@pathscale.com>
Signed-off-by: Hal Rosenstock <halr@voltaire.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

1 files changed, 9 insertions, 1 deletions

diff --git a/drivers/infiniband/core/mad.c b/drivers/infiniband/core/mad.c
index d393b504bf26..c82f47a66e48 100644
--- a/drivers/infiniband/core/mad.c
+++ b/drivers/infiniband/core/mad.c
@@ -665,7 +665,15 @@ static int handle_outgoing_dr_smp(struct ib_mad_agent_private *mad_agent_priv,
         struct ib_wc mad_wc;
         struct ib_send_wr *send_wr = &mad_send_wr->send_wr;
 
-        if (!smi_handle_dr_smp_send(smp, device->node_type, port_num)) {
+        /*
+         * Directed route handling starts if the initial LID routed part of
+         * a request or the ending LID routed part of a response is empty.
+         * If we are at the start of the LID routed part, don't update the
+         * hop_ptr or hop_cnt.  See section 14.2.2, Vol 1 IB spec.
+         */
+        if ((ib_get_smp_direction(smp) ? smp->dr_dlid : smp->dr_slid) ==
+             IB_LID_PERMISSIVE &&
+            !smi_handle_dr_smp_send(smp, device->node_type, port_num)) {
                 ret = -EINVAL;
                 printk(KERN_ERR PFX "Invalid directed route\n");
                 goto out;