Subject: Re: [PATCH] net: stmmac: dwmac-loongson: Set correct {tx,rx}_fifo_size

From: Simon Horman <[email-masked]>
Date: Wed, 22 Jan 2025 13:34:50 +0000

+ Feiyang Chen, Yanteng Si, Alexandre Torgue, Maxime Coquelin, Serge Semin,
  linux-arm-kernel

On Tue, Jan 21, 2025 at 05:37:03PM +0800, Huacai Chen wrote:
> Now for dwmac-loongson {tx,rx}_fifo_size are uninitialised, which means
> zero. This means dwmac-loongson doesn't support changing MTU, so set the
> correct tx_fifo_size and rx_fifo_size for it (16KB multiplied by channel
> counts).
> 
> Note: the Fixes tag is not exactly right, but it is a key commit of the
> dwmac-loongson series.
> 
> Cc: [email-masked]
> Fixes: ad72f783de06827a1f ("net: stmmac: Add multi-channel support")
> Signed-off-by: Chong Qiao <[email-masked]>
> Signed-off-by: Huacai Chen <[email-masked]>

Thanks, this change looks good to me.
And I agree that MTU setting cannot succeed without it.

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

Some process notes regarding Networking patches to keep
in mind for next time.

1. Please set the target tree. In this case, as this is a fix
   for code present in net. In general, otherwise it would be net-next.

   Subject: [PATCH net] ...

2. Please generate a CC list using

   ./scripts/get_maintainer.pl this.patch

   The b4 tool can help with this.

Link: https://docs.kernel.org/process/maintainer-netdev.html

> ---
>  drivers/net/ethernet/stmicro/stmmac/dwmac-loongson.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-loongson.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-loongson.c
> index bfe6e2d631bd..79acdf38c525 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/dwmac-loongson.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-loongson.c
> @@ -574,6 +574,9 @@ static int loongson_dwmac_probe(struct pci_dev *pdev, const struct pci_device_id
>  	if (ret)
>  		goto err_disable_device;
>  
> +	plat->tx_fifo_size = SZ_16K * plat->tx_queues_to_use;
> +	plat->rx_fifo_size = SZ_16K * plat->rx_queues_to_use;
> +
>  	if (dev_of_node(&pdev->dev))
>  		ret = loongson_dwmac_dt_config(pdev, plat, &res);
>  	else
> -- 
> 2.47.1
> 
>