Re: [PATCH net-next v4 1/2] net: ethernet: ti: am65-cpsw: update pri_thread_map as per IEEE802.1Q-2014

[Guillaume Nault <gnault@redhat.com>]

On Thu, Nov 14, 2024 at 03:36:52PM +0200, Roger Quadros wrote:
> IEEE802.1Q-2014 supersedes IEEE802.1D-2004. Now Priority Code Point (PCP)
> 2 is no longer at a lower priority than PCP 0. PCP 1 (Background) is still
> at a lower priority than PCP 0 (Best Effort).

Reviewed-by: Guillaume Nault <gnault@redhat.com>

> Reference:
> IEEE802.1Q-2014, Standard for Local and metropolitan area networks
>   Table I-2 - Traffic type acronyms
>   Table I-3 - Defining traffic types
> 
> Signed-off-by: Roger Quadros <rogerq@kernel.org>
> Reviewed-by: Siddharth Vadapalli <s-vadapalli@ti.com>
> ---
>  drivers/net/ethernet/ti/cpsw_ale.c | 36 ++++++++++++++++++++++--------------
>  1 file changed, 22 insertions(+), 14 deletions(-)
> 
> diff --git a/drivers/net/ethernet/ti/cpsw_ale.c b/drivers/net/ethernet/ti/cpsw_ale.c
> index 8d02d2b21429..9f79056b3f48 100644
> --- a/drivers/net/ethernet/ti/cpsw_ale.c
> +++ b/drivers/net/ethernet/ti/cpsw_ale.c
> @@ -1692,26 +1692,34 @@ static void cpsw_ale_policer_reset(struct cpsw_ale *ale)
>  void cpsw_ale_classifier_setup_default(struct cpsw_ale *ale, int num_rx_ch)
>  {
>  	int pri, idx;
> -	/* IEEE802.1D-2004, Standard for Local and metropolitan area networks
> -	 *    Table G-2 - Traffic type acronyms
> -	 *    Table G-3 - Defining traffic types
> -	 * User priority values 1 and 2 effectively communicate a lower
> -	 * priority than 0. In the below table 0 is assigned to higher priority
> -	 * thread than 1 and 2 wherever possible.
> -	 * The below table maps which thread the user priority needs to be
> +
> +	/* Reference:
> +	 * IEEE802.1Q-2014, Standard for Local and metropolitan area networks
> +	 *    Table I-2 - Traffic type acronyms
> +	 *    Table I-3 - Defining traffic types
> +	 * Section I.4 Traffic types and priority values, states:
> +	 * "0 is thus used both for default priority and for Best Effort, and
> +	 *  Background is associated with a priority value of 1. This means
> +	 * that the value 1 effectively communicates a lower priority than 0."
> +	 *
> +	 * In the table below, Priority Code Point (PCP) 0 is assigned
> +	 * to a higher priority thread than PCP 1 wherever possible.
> +	 * The table maps which thread the PCP traffic needs to be
>  	 * sent to for a given number of threads (RX channels). Upper threads
>  	 * have higher priority.
>  	 * e.g. if number of threads is 8 then user priority 0 will map to
> -	 * pri_thread_map[8-1][0] i.e. thread 2
> +	 * pri_thread_map[8-1][0] i.e. thread 1
>  	 */
> -	int pri_thread_map[8][8] = {	{ 0, 0, 0, 0, 0, 0, 0, 0, },
> +
> +	int pri_thread_map[8][8] = {   /* BK,BE,EE,CA,VI,VO,IC,NC */
> +					{ 0, 0, 0, 0, 0, 0, 0, 0, },
>  					{ 0, 0, 0, 0, 1, 1, 1, 1, },
>  					{ 0, 0, 0, 0, 1, 1, 2, 2, },
> -					{ 1, 0, 0, 1, 2, 2, 3, 3, },
> -					{ 1, 0, 0, 1, 2, 3, 4, 4, },
> -					{ 1, 0, 0, 2, 3, 4, 5, 5, },
> -					{ 1, 0, 0, 2, 3, 4, 5, 6, },
> -					{ 2, 0, 1, 3, 4, 5, 6, 7, } };
> +					{ 0, 0, 1, 1, 2, 2, 3, 3, },
> +					{ 0, 0, 1, 1, 2, 2, 3, 4, },
> +					{ 1, 0, 2, 2, 3, 3, 4, 5, },
> +					{ 1, 0, 2, 3, 4, 4, 5, 6, },
> +					{ 1, 0, 2, 3, 4, 5, 6, 7 } };
>  
>  	cpsw_ale_policer_reset(ale);
>  
> 
> -- 
> 2.34.1
>