From: AMEET M. PARANJAPE <aparanja@redhat.com>
Date: Fri, 7 Nov 2008 14:48:53 -0600
Subject: [openib] ehca: remove ref to QP if port activation fails
Message-id: 4914A9B5.6020302@REDHAT.COM
O-Subject: Re: [PATCH RHEL5.3 BZ469941] IB/ehca: remove reference to the QP in case of port activation failure
Bugzilla: 469941
RH-Acked-by: Doug Ledford <dledford@redhat.com>

RHBZ#:
======
https://bugzilla.redhat.com/show_bug.cgi?id=469941

Description:
===========
If the initialization of a special queue pair (QP) (e.g. AQP1) fails due to
a
software timeout,we have to remove the reference to that special QP struct
from
the port struct preventing the driver to access the QP, since it will be/has
been destroyed by the caller, ie in this case ib_mad.

RHEL Version Found:
================
RHEL 5.3 alpha and beta

kABI Status:
============
No symbols were harmed.

Brew:
=====
Built on all platforms.
http://brewweb.devel.redhat.com/brew/taskinfo?taskID=1556681

Upstream Status:
================
http://lkml.org/lkml/2008/11/4/178

Test Status:
============
On ppc64 system it occured that the ehca ports were not comming up in time.
A while after the timeout of the probe function, the "port up" event occured
and lead in some cases to a kernel panic.

With this patch the issue is not seen anymore.

diff --git a/drivers/infiniband/hw/ehca/ehca_irq.c b/drivers/infiniband/hw/ehca/ehca_irq.c
index 99642a6..4c57161 100644
--- a/drivers/infiniband/hw/ehca/ehca_irq.c
+++ b/drivers/infiniband/hw/ehca/ehca_irq.c
@@ -370,25 +370,27 @@ static void parse_ec(struct ehca_shca *shca, u64 eqe)
 	switch (ec) {
 	case 0x30: /* port availability change */
 		if (EHCA_BMASK_GET(NEQE_PORT_AVAILABILITY, eqe)) {
-			int suppress_event;
-			/* replay modify_qp for sqps */
-			spin_lock_irqsave(&sport->mod_sqp_lock, flags);
-			suppress_event = !sport->ibqp_sqp[IB_QPT_GSI];
-			if (sport->ibqp_sqp[IB_QPT_SMI])
-				ehca_recover_sqp(sport->ibqp_sqp[IB_QPT_SMI]);
-			if (!suppress_event)
-				ehca_recover_sqp(sport->ibqp_sqp[IB_QPT_GSI]);
-			spin_unlock_irqrestore(&sport->mod_sqp_lock, flags);
-
-			/* AQP1 was destroyed, ignore this event */
-			if (suppress_event)
-				break;
+			/* perform recovery only for port auto-detect mode */
+			if (ehca_nr_ports == -1) {
+				int suppress_event;
+				/* replay modify_qp for sqps */
+				spin_lock_irqsave(&sport->mod_sqp_lock, flags);
+				suppress_event = !sport->ibqp_sqp[IB_QPT_GSI];
+				if (sport->ibqp_sqp[IB_QPT_SMI])
+					ehca_recover_sqp(sport->ibqp_sqp[IB_QPT_SMI]);
+				if (!suppress_event)
+					ehca_recover_sqp(sport->ibqp_sqp[IB_QPT_GSI]);
+				spin_unlock_irqrestore(&sport->mod_sqp_lock, flags);
+
+				/* AQP1 was destroyed, ignore this event */
+				if (suppress_event)
+					break;
+			}
 
 			sport->port_state = IB_PORT_ACTIVE;
 			dispatch_port_event(shca, port, IB_EVENT_PORT_ACTIVE,
 					    "is active");
-			ehca_query_sma_attr(shca, port,
-					    &sport->saved_attr);
+			ehca_query_sma_attr(shca, port, &sport->saved_attr);
 		} else {
 			sport->port_state = IB_PORT_DOWN;
 			dispatch_port_event(shca, port, IB_EVENT_PORT_ERR,
diff --git a/drivers/infiniband/hw/ehca/ehca_qp.c b/drivers/infiniband/hw/ehca/ehca_qp.c
index 556de4c..f3ca3f6 100644
--- a/drivers/infiniband/hw/ehca/ehca_qp.c
+++ b/drivers/infiniband/hw/ehca/ehca_qp.c
@@ -847,6 +847,11 @@ static struct ehca_qp *internal_create_qp(
 	if (qp_type == IB_QPT_GSI) {
 		h_ret = ehca_define_sqp(shca, my_qp, init_attr);
 		if (h_ret != H_SUCCESS) {
+			kfree(my_qp->mod_qp_parm);
+			my_qp->mod_qp_parm = NULL;
+			/* the QP pointer is no longer valid */
+			shca->sport[init_attr->port_num - 1].ibqp_sqp[qp_type] =
+				NULL;
 			ret = ehca2ib_return_code(h_ret);
 			goto create_qp_exit6;
 		}