[PATCH] net: macb: Only disable NAPI on the actual error path

[PATCH] net: macb: Only disable NAPI on the actual error path

[Charles Keepax]

A recent change added a disable to NAPI into macb_open, this was
intended to only happen on the error path but accidentally applies
to all paths. This causes NAPI to be disabled on the success path, which
leads to the network to no longer functioning.

Fixes: 014406babc1f ("net: cadence: macb: disable NAPI on error")
Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
---
 drivers/net/ethernet/cadence/macb_main.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c
index 5b9d7c60eebc0..67933079aeea5 100644
--- a/drivers/net/ethernet/cadence/macb_main.c
+++ b/drivers/net/ethernet/cadence/macb_main.c
@@ -2565,15 +2565,14 @@ static int macb_open(struct net_device *dev)
 	if (bp->ptp_info)
 		bp->ptp_info->ptp_init(dev);
 
+	return 0;
+
 napi_exit:
 	for (q = 0, queue = bp->queues; q < bp->num_queues; ++q, ++queue)
 		napi_disable(&queue->napi);
 pm_exit:
-	if (err) {
-		pm_runtime_put_sync(&bp->pdev->dev);
-		return err;
-	}
-	return 0;
+	pm_runtime_put_sync(&bp->pdev->dev);
+	return err;
 }
 
 static int macb_close(struct net_device *dev)
-- 
2.11.0

Re: [PATCH] net: macb: Only disable NAPI on the actual error path

[LABBE Corentin]

On Mon, Jun 15, 2020 at 02:18:54PM +0100, Charles Keepax wrote:
> A recent change added a disable to NAPI into macb_open, this was
> intended to only happen on the error path but accidentally applies
> to all paths. This causes NAPI to be disabled on the success path, which
> leads to the network to no longer functioning.
> 
> Fixes: 014406babc1f ("net: cadence: macb: disable NAPI on error")
> Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
> ---
>  drivers/net/ethernet/cadence/macb_main.c | 9 ++++-----
>  1 file changed, 4 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c
> index 5b9d7c60eebc0..67933079aeea5 100644
> --- a/drivers/net/ethernet/cadence/macb_main.c
> +++ b/drivers/net/ethernet/cadence/macb_main.c
> @@ -2565,15 +2565,14 @@ static int macb_open(struct net_device *dev)
>  	if (bp->ptp_info)
>  		bp->ptp_info->ptp_init(dev);
>  
> +	return 0;
> +
>  napi_exit:
>  	for (q = 0, queue = bp->queues; q < bp->num_queues; ++q, ++queue)
>  		napi_disable(&queue->napi);
>  pm_exit:
> -	if (err) {
> -		pm_runtime_put_sync(&bp->pdev->dev);
> -		return err;
> -	}
> -	return 0;
> +	pm_runtime_put_sync(&bp->pdev->dev);
> +	return err;
>  }
>  
>  static int macb_close(struct net_device *dev)
> -- 
> 2.11.0
> 

Shame on me to not have see this.

With the fix it works.
Tested-by: Corentin Labbe <clabbe@baylibre.com>
Tested-on: qemu-xilinx-zynq-a9

Re: [PATCH] net: macb: Only disable NAPI on the actual error path

[David Miller]

From: Charles Keepax <ckeepax@opensource.cirrus.com>
Date: Mon, 15 Jun 2020 14:18:54 +0100

> A recent change added a disable to NAPI into macb_open, this was
> intended to only happen on the error path but accidentally applies
> to all paths. This causes NAPI to be disabled on the success path, which
> leads to the network to no longer functioning.
> 
> Fixes: 014406babc1f ("net: cadence: macb: disable NAPI on error")
> Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>

Applied, thank you.