[dpdk-dev] [PATCH v2] net/mlx4: fix port start fail after device removal

[Moti Haimovsky <motih@mellanox.com>]

In failsafe device start can be called for ports/devices that
had been plugged out.
This patch fixes mlx4 port start failure when called by the failsafe
PMD for removed devices.

Fixes: a6e8b01c3c26 ("net/mlx4: compact interrupt functions")
Cc: stable@dpdk.org

Signed-off-by: Moti Haimovsky <motih@mellanox.com>
---
V2:
Fixed commit message.
---
 drivers/net/mlx4/mlx4.c      | 10 ++++++++--
 drivers/net/mlx4/mlx4.h      |  2 ++
 drivers/net/mlx4/mlx4_intr.c | 43 ++++++++++++++++++++++++++++++++++++++++---
 3 files changed, 50 insertions(+), 5 deletions(-)

diff --git a/drivers/net/mlx4/mlx4.c b/drivers/net/mlx4/mlx4.c
index 61c5bf4..c67b221 100644
--- a/drivers/net/mlx4/mlx4.c
+++ b/drivers/net/mlx4/mlx4.c
@@ -108,7 +108,13 @@ struct mlx4_conf {
 		      " flow error type %d, cause %p, message: %s",
 		      -ret, strerror(-ret), error.type, error.cause,
 		      error.message ? error.message : "(unspecified)");
+		goto exit;
 	}
+	ret = mlx4_intr_install(priv);
+	if (ret)
+		ERROR("%p: interrupt handler installation failed",
+		     (void *)dev);
+exit:
 	return ret;
 }
 
@@ -141,7 +147,7 @@ struct mlx4_conf {
 		      (void *)dev, strerror(-ret));
 		goto err;
 	}
-	ret = mlx4_intr_install(priv);
+	ret = mlx4_intr_enable(priv);
 	if (ret) {
 		ERROR("%p: interrupt handler installation failed",
 		     (void *)dev);
@@ -187,7 +193,7 @@ struct mlx4_conf {
 	dev->rx_pkt_burst = mlx4_rx_burst_removed;
 	rte_wmb();
 	mlx4_flow_sync(priv, NULL);
-	mlx4_intr_uninstall(priv);
+	mlx4_intr_disable(priv);
 	mlx4_rss_deinit(priv);
 }
 
diff --git a/drivers/net/mlx4/mlx4.h b/drivers/net/mlx4/mlx4.h
index 99dc335..ab4f396 100644
--- a/drivers/net/mlx4/mlx4.h
+++ b/drivers/net/mlx4/mlx4.h
@@ -176,6 +176,8 @@ int mlx4_flow_ctrl_set(struct rte_eth_dev *dev,
 
 int mlx4_intr_uninstall(struct priv *priv);
 int mlx4_intr_install(struct priv *priv);
+int mlx4_intr_enable(struct priv *priv);
+void mlx4_intr_disable(struct priv *priv);
 int mlx4_rx_intr_disable(struct rte_eth_dev *dev, uint16_t idx);
 int mlx4_rx_intr_enable(struct rte_eth_dev *dev, uint16_t idx);
 
diff --git a/drivers/net/mlx4/mlx4_intr.c b/drivers/net/mlx4/mlx4_intr.c
index 9becee4..eeab625 100644
--- a/drivers/net/mlx4/mlx4_intr.c
+++ b/drivers/net/mlx4/mlx4_intr.c
@@ -73,6 +73,8 @@
 {
 	struct rte_intr_handle *intr_handle = &priv->intr_handle;
 
+	if (intr_handle == NULL || intr_handle->intr_vec == NULL)
+		return;
 	rte_intr_free_epoll_fd(intr_handle);
 	free(intr_handle->intr_vec);
 	intr_handle->nb_efd = 0;
@@ -291,7 +293,7 @@
 	}
 	rte_eal_alarm_cancel((void (*)(void *))mlx4_link_status_alarm, priv);
 	priv->intr_alarm = 0;
-	mlx4_rx_intr_vec_disable(priv);
+	mlx4_intr_disable(priv);
 	rte_errno = err;
 	return 0;
 }
@@ -313,8 +315,6 @@
 	int rc;
 
 	mlx4_intr_uninstall(priv);
-	if (intr_conf->rxq && mlx4_rx_intr_vec_enable(priv) < 0)
-		goto error;
 	if (intr_conf->lsc | intr_conf->rmv) {
 		priv->intr_handle.fd = priv->ctx->async_fd;
 		rc = rte_intr_callback_register(&priv->intr_handle,
@@ -395,3 +395,40 @@
 	}
 	return -ret;
 }
+
+/**
+ * Enable datapath interrupts.
+ *
+ * @param priv
+ *   Pointer to private structure.
+ *
+ * @return
+ *   0 on success, negative errno value otherwise and rte_errno is set.
+ */
+int
+mlx4_intr_enable(struct priv *priv)
+{
+	const struct rte_intr_conf *const intr_conf =
+		&priv->dev->data->dev_conf.intr_conf;
+
+	if (intr_conf->rxq && mlx4_rx_intr_vec_enable(priv) < 0)
+		goto error;
+	return 0;
+error:
+	return -rte_errno;
+}
+
+/**
+ * Disable datapath interrupts, keeping other interrupts intact.
+ *
+ * @param priv
+ *   Pointer to private structure.
+ */
+void
+mlx4_intr_disable(struct priv *priv)
+{
+	int err = rte_errno; /* Make sure rte_errno remains unchanged. */
+
+	mlx4_rx_intr_vec_disable(priv);
+	rte_errno = err;
+}
-- 
1.8.3.1