Subject: Re: [PATCH net-next v2 1/7] net: ethernet: ti: am65-cpsw: Introduce multi queue Rx

From: Simon Horman <[email-masked]>
Date: Mon, 1 Jul 2024 08:35:19 +0100

On Fri, Jun 28, 2024 at 03:01:50PM +0300, Roger Quadros wrote:
> am65-cpsw can support up to 8 queues at Rx.
> Use a macro AM65_CPSW_MAX_RX_QUEUES to indicate that.
> As there is only one DMA channel for RX traffic, the
> 8 queues come as 8 flows in that channel.
> 
> By default, we will start with 1 flow as defined by the
> macro AM65_CPSW_DEFAULT_RX_CHN_FLOWS.
> 
> User can change the number of flows by ethtool like so
> 'ethtool -L ethx rx <N>'
> 
> All traffic will still come on flow 0. To get traffic on
> different flows the Classifiers will need to be set up.
> 
> Signed-off-by: Roger Quadros <[email-masked]>

Hi Roger,

The nit's below notwithstanding, this looks good to me.

Reviewed-by: Simon Horman <[email-masked]>

> ---
>  drivers/net/ethernet/ti/am65-cpsw-ethtool.c |  59 +++--
>  drivers/net/ethernet/ti/am65-cpsw-nuss.c    | 358 ++++++++++++++++------------
>  drivers/net/ethernet/ti/am65-cpsw-nuss.h    |  35 +--
>  3 files changed, 272 insertions(+), 180 deletions(-)
> 
> diff --git a/drivers/net/ethernet/ti/am65-cpsw-ethtool.c b/drivers/net/ethernet/ti/am65-cpsw-ethtool.c
> index a1d0935d1ebe..3106bf07eb1a 100644
> --- a/drivers/net/ethernet/ti/am65-cpsw-ethtool.c
> +++ b/drivers/net/ethernet/ti/am65-cpsw-ethtool.c
> @@ -429,7 +429,7 @@ static void am65_cpsw_get_channels(struct net_device *ndev,
>  
>  	ch->max_rx = AM65_CPSW_MAX_RX_QUEUES;
>  	ch->max_tx = AM65_CPSW_MAX_TX_QUEUES;
> -	ch->rx_count = AM65_CPSW_MAX_RX_QUEUES;
> +	ch->rx_count = common->rx_ch_num_flows;
>  	ch->tx_count = common->tx_ch_num;
>  }
>  
> @@ -448,8 +448,9 @@ static int am65_cpsw_set_channels(struct net_device *ndev,
>  		return -EBUSY;
>  
>  	am65_cpsw_nuss_remove_tx_chns(common);
> +	am65_cpsw_nuss_remove_rx_chns(common);
>  
> -	return am65_cpsw_nuss_update_tx_chns(common, chs->tx_count);
> +	return am65_cpsw_nuss_update_tx_rx_chns(common, chs->tx_count, chs->rx_count);

nit: This line could be trivially wrapped to be <= 80 columns wide,
     as is still preferred by networking code. Likewise in a few
     other places in this patch (set).

     Flagged by checkpatch.pl --max-line-length=80

>  }
>  
>  static void
> @@ -921,10 +922,12 @@ static int am65_cpsw_get_coalesce(struct net_device *ndev, struct ethtool_coales
>  {
>  	struct am65_cpsw_common *common = am65_ndev_to_common(ndev);
>  	struct am65_cpsw_tx_chn *tx_chn;
> +	struct am65_cpsw_rx_flow *rx_flow;

nit: Please consider arranging local variables in reverse xmas tree order -
     longest line to shortest - in networking code.

     Edward Cree's tool can be helpful here:
     https://github.com/ecree-solarflare/xmastree

>  
>  	tx_chn = &common->tx_chns[0];
> +	rx_flow = &common->rx_chns.flows[0];
>  
> -	coal->rx_coalesce_usecs = common->rx_pace_timeout / 1000;
> +	coal->rx_coalesce_usecs = rx_flow->rx_pace_timeout / 1000;
>  	coal->tx_coalesce_usecs = tx_chn->tx_pace_timeout / 1000;
>  
>  	return 0;

...