Re: [PATCH net 2/2] net: stmmac: Limit the number of MTL queues to maximum value

[Furong Xu <0x1207@gmail.com>]

On Thu, 16 Jan 2025 11:08:53 +0900, Kunihiko Hayashi <hayashi.kunihiko@socionext.com> wrote:

> The number of MTL queues to use is specified by the parameter
> "snps,{tx,rx}-queues-to-use" from the platform layer.
> 
> However, the maximum number of queues is determined by
> the macro MTL_MAX_{TX,RX}_QUEUES. It's appropriate to limit the
> values not to exceed the upper limit values.
> 

The Fixes: tag is required too.

> Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
> ---
>  drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
> index ad868e8d195d..471eb1a99d90 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
> @@ -165,6 +165,8 @@ static int stmmac_mtl_setup(struct platform_device *pdev,
>  	if (of_property_read_u32(rx_node, "snps,rx-queues-to-use",
>  				 &plat->rx_queues_to_use))
>  		plat->rx_queues_to_use = 1;
> +	if (plat->rx_queues_to_use > MTL_MAX_RX_QUEUES)
> +		plat->rx_queues_to_use = MTL_MAX_RX_QUEUES;

MTL_MAX_RX_QUEUES, MTL_MAX_TX_QUEUES and STMMAC_CH_MAX are defined to 8,
this is correct for gmac4, but xgmac has 16 channels at most.

Drop these legacy defines and always use
priv->dma_cap.number_rx_queues,
priv->dma_cap.number_tx_queues,
priv->dma_cap.number_tx_channel,
priv->dma_cap.number_rx_channel,
seems like a good option.

>  
>  	if (of_property_read_bool(rx_node, "snps,rx-sched-sp"))
>  		plat->rx_sched_algorithm = MTL_RX_ALGORITHM_SP;
> @@ -224,6 +226,8 @@ static int stmmac_mtl_setup(struct platform_device *pdev,
>  	if (of_property_read_u32(tx_node, "snps,tx-queues-to-use",
>  				 &plat->tx_queues_to_use))
>  		plat->tx_queues_to_use = 1;
> +	if (plat->tx_queues_to_use > MTL_MAX_TX_QUEUES)
> +		plat->tx_queues_to_use = MTL_MAX_TX_QUEUES;
>  
>  	if (of_property_read_bool(tx_node, "snps,tx-sched-wrr"))
>  		plat->tx_sched_algorithm = MTL_TX_ALGORITHM_WRR;