patches for DPDK stable branches
 help / color / mirror / Atom feed
* [dpdk-stable] [PATCH] net/mlx5: fix inconsistent link status
@ 2017-02-21  7:23 shahafs
  2017-02-21  7:31 ` Yuanhan Liu
  0 siblings, 1 reply; 2+ messages in thread
From: shahafs @ 2017-02-21  7:23 UTC (permalink / raw)
  To: yuanhan.liu, stable; +Cc: Shahaf Shuler

From: Shahaf Shuler <shahafs@mellanox.com>

[ backported from upstream commit a9f2fbc42f0c58df614896a407fd694899315233 ]

Querying the link status can end up being in an inconsistent state,
like the port is reporting speed although it is down.

For this case another query is scheduled.

A race condition can occur between the scheduled query and link
status interrupt handlers.

When the scheduled query by-pass interrupt handlers, the link status
will be stuck in an inconsistent state.

This patch addresses the race condition by not blocking link status
queries in case delayed query is used.

Fixes: 198a3c339a8f ("mlx5: handle link status interrupts")
Cc: stable@dpdk.org

Signed-off-by: Shahaf Shuler <shahafs@mellanox.com>
Acked-by: Nelio Laranjeiro <nelio.laranjeiro@6wind.com>
---
 drivers/net/mlx5/mlx5_ethdev.c | 26 +++++++++++---------------
 1 file changed, 11 insertions(+), 15 deletions(-)

diff --git a/drivers/net/mlx5/mlx5_ethdev.c b/drivers/net/mlx5/mlx5_ethdev.c
index a709a3a..06cfd01 100644
--- a/drivers/net/mlx5/mlx5_ethdev.c
+++ b/drivers/net/mlx5/mlx5_ethdev.c
@@ -1183,7 +1183,7 @@ struct priv *
 priv_dev_link_status_handler(struct priv *priv, struct rte_eth_dev *dev)
 {
 	struct ibv_async_event event;
-	int port_change = 0;
+	struct rte_eth_link *link = &dev->data->dev_link;
 	int ret = 0;
 
 	/* Read all message and acknowledge them. */
@@ -1191,29 +1191,24 @@ struct priv *
 		if (ibv_get_async_event(priv->ctx, &event))
 			break;
 
-		if (event.event_type == IBV_EVENT_PORT_ACTIVE ||
-		    event.event_type == IBV_EVENT_PORT_ERR)
-			port_change = 1;
-		else
+		if (event.event_type != IBV_EVENT_PORT_ACTIVE &&
+		    event.event_type != IBV_EVENT_PORT_ERR)
 			DEBUG("event type %d on port %d not handled",
 			      event.event_type, event.element.port_num);
 		ibv_ack_async_event(&event);
 	}
-
-	if (port_change ^ priv->pending_alarm) {
-		struct rte_eth_link *link = &dev->data->dev_link;
-
-		priv->pending_alarm = 0;
-		mlx5_link_update_unlocked(dev, 0);
-		if (((link->link_speed == 0) && link->link_status) ||
-		    ((link->link_speed != 0) && !link->link_status)) {
+	mlx5_link_update(dev, 0);
+	if (((link->link_speed == 0) && link->link_status) ||
+	    ((link->link_speed != 0) && !link->link_status)) {
+		if (!priv->pending_alarm) {
 			/* Inconsistent status, check again later. */
 			priv->pending_alarm = 1;
 			rte_eal_alarm_set(MLX5_ALARM_TIMEOUT_US,
 					  mlx5_dev_link_status_handler,
 					  dev);
-		} else
-			ret = 1;
+		}
+	} else {
+		ret = 1;
 	}
 	return ret;
 }
@@ -1233,6 +1228,7 @@ struct priv *
 
 	priv_lock(priv);
 	assert(priv->pending_alarm == 1);
+	priv->pending_alarm = 0;
 	ret = priv_dev_link_status_handler(priv, dev);
 	priv_unlock(priv);
 	if (ret)
-- 
1.8.3.1

^ permalink raw reply	[flat|nested] 2+ messages in thread

* Re: [dpdk-stable] [PATCH] net/mlx5: fix inconsistent link status
  2017-02-21  7:23 [dpdk-stable] [PATCH] net/mlx5: fix inconsistent link status shahafs
@ 2017-02-21  7:31 ` Yuanhan Liu
  0 siblings, 0 replies; 2+ messages in thread
From: Yuanhan Liu @ 2017-02-21  7:31 UTC (permalink / raw)
  To: shahafs; +Cc: stable

On Tue, Feb 21, 2017 at 09:23:29AM +0200, shahafs wrote:
> From: Shahaf Shuler <shahafs@mellanox.com>
> 
> [ backported from upstream commit a9f2fbc42f0c58df614896a407fd694899315233 ]

Applied to dpdk-stable/16.11.

Thanks for the backport.

	--yliu

> 
> Querying the link status can end up being in an inconsistent state,
> like the port is reporting speed although it is down.
> 
> For this case another query is scheduled.
> 
> A race condition can occur between the scheduled query and link
> status interrupt handlers.
> 
> When the scheduled query by-pass interrupt handlers, the link status
> will be stuck in an inconsistent state.
> 
> This patch addresses the race condition by not blocking link status
> queries in case delayed query is used.
> 
> Fixes: 198a3c339a8f ("mlx5: handle link status interrupts")
> Cc: stable@dpdk.org
> 
> Signed-off-by: Shahaf Shuler <shahafs@mellanox.com>
> Acked-by: Nelio Laranjeiro <nelio.laranjeiro@6wind.com>
> ---
>  drivers/net/mlx5/mlx5_ethdev.c | 26 +++++++++++---------------
>  1 file changed, 11 insertions(+), 15 deletions(-)
> 
> diff --git a/drivers/net/mlx5/mlx5_ethdev.c b/drivers/net/mlx5/mlx5_ethdev.c
> index a709a3a..06cfd01 100644
> --- a/drivers/net/mlx5/mlx5_ethdev.c
> +++ b/drivers/net/mlx5/mlx5_ethdev.c
> @@ -1183,7 +1183,7 @@ struct priv *
>  priv_dev_link_status_handler(struct priv *priv, struct rte_eth_dev *dev)
>  {
>  	struct ibv_async_event event;
> -	int port_change = 0;
> +	struct rte_eth_link *link = &dev->data->dev_link;
>  	int ret = 0;
>  
>  	/* Read all message and acknowledge them. */
> @@ -1191,29 +1191,24 @@ struct priv *
>  		if (ibv_get_async_event(priv->ctx, &event))
>  			break;
>  
> -		if (event.event_type == IBV_EVENT_PORT_ACTIVE ||
> -		    event.event_type == IBV_EVENT_PORT_ERR)
> -			port_change = 1;
> -		else
> +		if (event.event_type != IBV_EVENT_PORT_ACTIVE &&
> +		    event.event_type != IBV_EVENT_PORT_ERR)
>  			DEBUG("event type %d on port %d not handled",
>  			      event.event_type, event.element.port_num);
>  		ibv_ack_async_event(&event);
>  	}
> -
> -	if (port_change ^ priv->pending_alarm) {
> -		struct rte_eth_link *link = &dev->data->dev_link;
> -
> -		priv->pending_alarm = 0;
> -		mlx5_link_update_unlocked(dev, 0);
> -		if (((link->link_speed == 0) && link->link_status) ||
> -		    ((link->link_speed != 0) && !link->link_status)) {
> +	mlx5_link_update(dev, 0);
> +	if (((link->link_speed == 0) && link->link_status) ||
> +	    ((link->link_speed != 0) && !link->link_status)) {
> +		if (!priv->pending_alarm) {
>  			/* Inconsistent status, check again later. */
>  			priv->pending_alarm = 1;
>  			rte_eal_alarm_set(MLX5_ALARM_TIMEOUT_US,
>  					  mlx5_dev_link_status_handler,
>  					  dev);
> -		} else
> -			ret = 1;
> +		}
> +	} else {
> +		ret = 1;
>  	}
>  	return ret;
>  }
> @@ -1233,6 +1228,7 @@ struct priv *
>  
>  	priv_lock(priv);
>  	assert(priv->pending_alarm == 1);
> +	priv->pending_alarm = 0;
>  	ret = priv_dev_link_status_handler(priv, dev);
>  	priv_unlock(priv);
>  	if (ret)
> -- 
> 1.8.3.1

^ permalink raw reply	[flat|nested] 2+ messages in thread

end of thread, other threads:[~2017-02-21  7:29 UTC | newest]

Thread overview: 2+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2017-02-21  7:23 [dpdk-stable] [PATCH] net/mlx5: fix inconsistent link status shahafs
2017-02-21  7:31 ` Yuanhan Liu

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).