[dpdk-dev] [PATCH 06/12] net/cxgbe: avoid polling link status before device start

[Rahul Lakkireddy <rahul.lakkireddy@chelsio.com>]

Link updates come in firmware event queue, which is only created
when device starts. So, don't poll for link status if firmware
event queue is not yet created.

This fixes NULL dereference when accessing non existent firmware
event queue.

Cc: stable@dpdk.org
Fixes: 265af08e75ba ("net/cxgbe: add link up and down ops")

Signed-off-by: Rahul Lakkireddy <rahul.lakkireddy@chelsio.com>
---
 drivers/net/cxgbe/cxgbe_ethdev.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/net/cxgbe/cxgbe_ethdev.c b/drivers/net/cxgbe/cxgbe_ethdev.c
index fb174f8d4..381dd273d 100644
--- a/drivers/net/cxgbe/cxgbe_ethdev.c
+++ b/drivers/net/cxgbe/cxgbe_ethdev.c
@@ -204,6 +204,9 @@ int cxgbe_dev_link_update(struct rte_eth_dev *eth_dev,
 	u8 old_link = pi->link_cfg.link_ok;
 
 	for (i = 0; i < CXGBE_LINK_STATUS_POLL_CNT; i++) {
+		if (!s->fw_evtq.desc)
+			break;
+
 		cxgbe_poll(&s->fw_evtq, NULL, budget, &work_done);
 
 		/* Exit if link status changed or always forced up */
@@ -237,6 +240,9 @@ int cxgbe_dev_set_link_up(struct rte_eth_dev *dev)
 	struct sge *s = &adapter->sge;
 	int ret;
 
+	if (!s->fw_evtq.desc)
+		return -ENOMEM;
+
 	/* Flush all link events */
 	cxgbe_poll(&s->fw_evtq, NULL, budget, &work_done);
 
@@ -263,6 +269,9 @@ int cxgbe_dev_set_link_down(struct rte_eth_dev *dev)
 	struct sge *s = &adapter->sge;
 	int ret;
 
+	if (!s->fw_evtq.desc)
+		return -ENOMEM;
+
 	/* Flush all link events */
 	cxgbe_poll(&s->fw_evtq, NULL, budget, &work_done);
 
-- 
2.18.0