Re: [PATCH net-next] net: stmmac: mostly remove "buf_sz"

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

On Wed, 05 Mar 2025 17:54:21 +0000
"Russell King (Oracle)" <rmk+kernel@armlinux.org.uk> wrote:

> The "buf_sz" parameter is not used in the stmmac driver - there is one
> place where the value of buf_sz is validated, and two places where it
> is written. It is otherwise unused.
> 
> Remove these accesses. However, leave the module parameter in place as
> removing it could cause module load to fail, breaking user setups.
> 
> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
> ---
>  drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 7 +------
>  1 file changed, 1 insertion(+), 6 deletions(-)
> 
> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> index cb5099caecd0..037039a9a33b 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> @@ -101,6 +101,7 @@ static int tc = TC_DEFAULT;
>  module_param(tc, int, 0644);
>  MODULE_PARM_DESC(tc, "DMA threshold control value");
>  
> +/* This is unused */
>  #define	DEFAULT_BUFSIZE	1536
>  static int buf_sz = DEFAULT_BUFSIZE;
>  module_param(buf_sz, int, 0644);
> @@ -218,8 +219,6 @@ static void stmmac_verify_args(void)
>  {
>  	if (unlikely(watchdog < 0))
>  		watchdog = TX_TIMEO;
> -	if (unlikely((buf_sz < DEFAULT_BUFSIZE) || (buf_sz > BUF_SIZE_16KiB)))
> -		buf_sz = DEFAULT_BUFSIZE;
>  	if (unlikely((pause < 0) || (pause > 0xffff)))
>  		pause = PAUSE_TIME;
>  
> @@ -4018,7 +4017,6 @@ static int __stmmac_open(struct net_device *dev,
>  		}
>  	}
>  
> -	buf_sz = dma_conf->dma_buf_sz;
>  	for (int i = 0; i < MTL_MAX_TX_QUEUES; i++)
>  		if (priv->dma_conf.tx_queue[i].tbs & STMMAC_TBS_EN)
>  			dma_conf->tx_queue[i].tbs = priv->dma_conf.tx_queue[i].tbs;
> @@ -7973,9 +7971,6 @@ static int __init stmmac_cmdline_opt(char *str)
>  		} else if (!strncmp(opt, "phyaddr:", 8)) {
>  			if (kstrtoint(opt + 8, 0, &phyaddr))
>  				goto err;
> -		} else if (!strncmp(opt, "buf_sz:", 7)) {
> -			if (kstrtoint(opt + 7, 0, &buf_sz))
> -				goto err;
>  		} else if (!strncmp(opt, "tc:", 3)) {
>  			if (kstrtoint(opt + 3, 0, &tc))
>  				goto err;

Reviewed-by: Furong Xu <0x1207@gmail.com>