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

[Roger Quadros <rogerq@kernel.org>]

Hi Simon,

On 01/07/2024 10:35, Simon Horman wrote:
> 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 <rogerq@kernel.org>
> 
> Hi Roger,
> 
> The nit's below notwithstanding, this looks good to me.
> 
> Reviewed-by: Simon Horman <horms@kernel.org>
> 
> 
>> ---
>>  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).

will fix.

> 
>      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.

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

Thanks for this tip. I will use this in my workflow.

> 
>>  
>>  	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;
> 
> ...

-- 
cheers,
-roger