From ae16bf15374d8b055e040ac6f3f1147ab1c9bb7d Mon Sep 17 00:00:00 2001
From: Sukadev Bhattiprolu <sukadev@linux.ibm.com>
Date: Thu, 24 Feb 2022 22:23:56 -0800
Subject: [PATCH] ibmvnic: init init_done_rc earlier

References: bsc#1196516 ltc#196391
Patch-mainline: queued
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net.git
Git-commit: ae16bf15374d8b055e040ac6f3f1147ab1c9bb7d

We currently initialize the ->init_done completion/return code fields
before issuing a CRQ_INIT command. But if we get a transport event soon
after registering the CRQ the taskslet may already have recorded the
completion and error code. If we initialize here, we might overwrite/
lose that and end up issuing the CRQ_INIT only to timeout later.

If that timeout happens during probe, we will leave the adapter in the
DOWN state rather than retrying to register/init the CRQ.

Initialize the completion before registering the CRQ so we don't lose
the notification.

Fixes: 032c5e82847a ("Driver for IBM System i/p VNIC protocol")
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Michal Suchanek <msuchanek@suse.de>
---
 drivers/net/ethernet/ibm/ibmvnic.c | 26 +++++++++++++++++++++-----
 1 file changed, 21 insertions(+), 5 deletions(-)

diff --git a/drivers/net/ethernet/ibm/ibmvnic.c b/drivers/net/ethernet/ibm/ibmvnic.c
index a7b03ca109d8..16a8f92adbda 100644
--- a/drivers/net/ethernet/ibm/ibmvnic.c
+++ b/drivers/net/ethernet/ibm/ibmvnic.c
@@ -2212,6 +2212,19 @@ static const char *reset_reason_to_string(enum ibmvnic_reset_reason reason)
 	return "UNKNOWN";
 }
 
+/*
+ * Initialize the init_done completion and return code values. We
+ * can get a transport event just after registering the CRQ and the
+ * tasklet will use this to communicate the transport event. To ensure
+ * we don't miss the notification/error, initialize these _before_
+ * regisering the CRQ.
+ */
+static inline void reinit_init_done(struct ibmvnic_adapter *adapter)
+{
+	reinit_completion(&adapter->init_done);
+	adapter->init_done_rc = 0;
+}
+
 /*
  * do_reset returns zero if we are able to keep processing reset events, or
  * non-zero if we hit a fatal error and must halt.
@@ -2318,6 +2331,8 @@ static int do_reset(struct ibmvnic_adapter *adapter,
 		 */
 		adapter->state = VNIC_PROBED;
 
+		reinit_init_done(adapter);
+
 		if (adapter->reset_reason == VNIC_RESET_CHANGE_PARAM) {
 			rc = init_crq_queue(adapter);
 		} else if (adapter->reset_reason == VNIC_RESET_MOBILITY) {
@@ -2461,7 +2476,8 @@ static int do_hard_reset(struct ibmvnic_adapter *adapter,
 	 */
 	adapter->state = VNIC_PROBED;
 
-	reinit_completion(&adapter->init_done);
+	reinit_init_done(adapter);
+
 	rc = init_crq_queue(adapter);
 	if (rc) {
 		netdev_err(adapter->netdev,
@@ -5679,10 +5695,6 @@ static int ibmvnic_reset_init(struct ibmvnic_adapter *adapter, bool reset)
 
 	adapter->from_passive_init = false;
 
-	if (reset)
-		reinit_completion(&adapter->init_done);
-
-	adapter->init_done_rc = 0;
 	rc = ibmvnic_send_crq_init(adapter);
 	if (rc) {
 		dev_err(dev, "Send crq init failed with error %d\n", rc);
@@ -5696,12 +5708,14 @@ static int ibmvnic_reset_init(struct ibmvnic_adapter *adapter, bool reset)
 
 	if (adapter->init_done_rc) {
 		release_crq_queue(adapter);
+		dev_err(dev, "CRQ-init failed, %d\n", adapter->init_done_rc);
 		return adapter->init_done_rc;
 	}
 
 	if (adapter->from_passive_init) {
 		adapter->state = VNIC_OPEN;
 		adapter->from_passive_init = false;
+		dev_err(dev, "CRQ-init failed, passive-init\n");
 		return -EINVAL;
 	}
 
@@ -5795,6 +5809,8 @@ static int ibmvnic_probe(struct vio_dev *dev, const struct vio_device_id *id)
 
 	init_success = false;
 	do {
+		reinit_init_done(adapter);
+
 		rc = init_crq_queue(adapter);
 		if (rc) {
 			dev_err(&dev->dev, "Couldn't initialize crq. rc=%d\n",
-- 
2.34.1