netdev - Re: [PATCH 3/3] net: lantiq: Use napi_complete

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Date:   Sun, 16 Aug 2020 11:07:03 -0700
From:   Eric Dumazet <eric.dumazet@...il.com>
To:     Hauke Mehrtens <hauke@...ke-m.de>, davem@...emloft.net
Cc:     kuba@...nel.org, netdev@...r.kernel.org,
        martin.blumenstingl@...glemail.com
Subject: Re: [PATCH 3/3] net: lantiq: Use napi_complete_done()



On 8/15/20 11:33 AM, Hauke Mehrtens wrote:
> Use napi_complete_done() and activate the interrupts when this function
> returns true. This way the generic NAPI code can take care of activating
> the interrupts.
> 
> Signed-off-by: Hauke Mehrtens <hauke@...ke-m.de>
> ---
>  drivers/net/ethernet/lantiq_xrx200.c | 8 ++------
>  1 file changed, 2 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/net/ethernet/lantiq_xrx200.c b/drivers/net/ethernet/lantiq_xrx200.c
> index f34e4dc8c661..674ffb2ecd9a 100644
> --- a/drivers/net/ethernet/lantiq_xrx200.c
> +++ b/drivers/net/ethernet/lantiq_xrx200.c
> @@ -229,10 +229,8 @@ static int xrx200_poll_rx(struct napi_struct *napi, int budget)
>  		}
>  	}
>  
> -	if (rx < budget) {
> -		napi_complete(&ch->napi);
> +	if (napi_complete_done(&ch->napi, rx))
>  		ltq_dma_enable_irq(&ch->dma);
> -	}
>  
>  	return rx;
>  }
> @@ -271,10 +269,8 @@ static int xrx200_tx_housekeeping(struct napi_struct *napi, int budget)
>  	if (netif_queue_stopped(net_dev))
>  		netif_wake_queue(net_dev);
>  
> -	if (pkts < budget) {
> -		napi_complete(&ch->napi);
> +	if (napi_complete_done(&ch->napi, pkts))
>  		ltq_dma_enable_irq(&ch->dma);
> -	}
>  
>  	return pkts;
>  }
> 


This looks buggy to me.

Please look again to other implementations for a correct usage.