Re: [PATCH net] net: rswitch: Fix error path in rswitch_start_xmit()

From: Sergey Shtylyov <s.shtylyov@omp.ru>
To: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>,
	<davem@davemloft.net>, <edumazet@google.com>, <kuba@kernel.org>,
	<pabeni@redhat.com>
Cc: <netdev@vger.kernel.org>, <linux-renesas-soc@vger.kernel.org>
Subject: Re: [PATCH net] net: rswitch: Fix error path in rswitch_start_xmit()
Date: Tue, 21 Nov 2023 11:55:41 +0300	[thread overview]
Message-ID: <7b8197aa-edb8-76ed-57be-6fd8ab247a9c@omp.ru> (raw)
In-Reply-To: <20231121055255.3627949-1-yoshihiro.shimoda.uh@renesas.com>

On 11/21/23 8:52 AM, Yoshihiro Shimoda wrote:

> This .ndo_start_xmit() function should return netdev_tx_t value,
> not -ENOMEM. Also, before returning the function, dev_kfree_skb_any()
> should be called. So, fix them.

   Sounds like 2 separate issues -- each needing a patch of its own...

> Fixes: 33f5d733b589 ("net: renesas: rswitch: Improve TX timestamp accuracy")
> Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
> ---
>  drivers/net/ethernet/renesas/rswitch.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/ethernet/renesas/rswitch.c b/drivers/net/ethernet/renesas/rswitch.c
> index 43a7795d6591..fc9dcf5fa166 100644
> --- a/drivers/net/ethernet/renesas/rswitch.c
> +++ b/drivers/net/ethernet/renesas/rswitch.c
> @@ -1535,7 +1535,8 @@ static netdev_tx_t rswitch_start_xmit(struct sk_buff *skb, struct net_device *nd
>  		ts_info = kzalloc(sizeof(*ts_info), GFP_ATOMIC);
>  		if (!ts_info) {
>  			dma_unmap_single(ndev->dev.parent, dma_addr, skb->len, DMA_TO_DEVICE);
> -			return -ENOMEM;
> +			dev_kfree_skb_any(skb);
> +			return ret;

   Looks like we have the same error path as when dma_mapping_error()
returns error. Shouldn't we use *goto*? Although probably can be done
later, as a cleanup...

[...]

MBR, Sergey