Refactor code to support Jumbo frame functionality by adding a member
variable in the fec_enet_private structure to store PKT_MAXBUF_SIZE.

Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Wei Fang <wei.fang@nxp.com>
Signed-off-by: Shenwei Wang <shenwei.wang@nxp.com>
---
 drivers/net/ethernet/freescale/fec.h      | 1 +
 drivers/net/ethernet/freescale/fec_main.c | 9 +++++----
 2 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/freescale/fec.h b/drivers/net/ethernet/freescale/fec.h
index 5c8fdcef759b..2969088dda09 100644
--- a/drivers/net/ethernet/freescale/fec.h
+++ b/drivers/net/ethernet/freescale/fec.h
@@ -619,6 +619,7 @@ struct fec_enet_private {
 
 	unsigned int total_tx_ring_size;
 	unsigned int total_rx_ring_size;
+	unsigned int max_buf_size;
 
 	struct	platform_device *pdev;
 
diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c
index 1383918f8a3f..5a21000aca59 100644
--- a/drivers/net/ethernet/freescale/fec_main.c
+++ b/drivers/net/ethernet/freescale/fec_main.c
@@ -253,7 +253,7 @@ MODULE_PARM_DESC(macaddr, "FEC Ethernet MAC address");
 #if defined(CONFIG_M523x) || defined(CONFIG_M527x) || defined(CONFIG_M528x) || \
     defined(CONFIG_M520x) || defined(CONFIG_M532x) || defined(CONFIG_ARM) || \
     defined(CONFIG_ARM64)
-#define	OPT_FRAME_SIZE	(PKT_MAXBUF_SIZE << 16)
+#define	OPT_FRAME_SIZE	(fep->max_buf_size << 16)
 #else
 #define	OPT_FRAME_SIZE	0
 #endif
@@ -1083,7 +1083,7 @@ static void fec_enet_enable_ring(struct net_device *ndev)
 	for (i = 0; i < fep->num_rx_queues; i++) {
 		rxq = fep->rx_queue[i];
 		writel(rxq->bd.dma, fep->hwp + FEC_R_DES_START(i));
-		writel(PKT_MAXBUF_SIZE, fep->hwp + FEC_R_BUFF_SIZE(i));
+		writel(fep->max_buf_size, fep->hwp + FEC_R_BUFF_SIZE(i));
 
 		/* enable DMA1/2 */
 		if (i)
@@ -1191,7 +1191,7 @@ fec_restart(struct net_device *ndev)
 		else
 			val &= ~FEC_RACC_OPTIONS;
 		writel(val, fep->hwp + FEC_RACC);
-		writel(PKT_MAXBUF_SIZE, fep->hwp + FEC_FTRL);
+		writel(fep->max_buf_size, fep->hwp + FEC_FTRL);
 	}
 #endif
 
@@ -4559,7 +4559,8 @@ fec_probe(struct platform_device *pdev)
 	fec_enet_clk_enable(ndev, false);
 	pinctrl_pm_select_sleep_state(&pdev->dev);
 
-	ndev->max_mtu = PKT_MAXBUF_SIZE - ETH_HLEN - ETH_FCS_LEN;
+	fep->max_buf_size = PKT_MAXBUF_SIZE;
+	ndev->max_mtu = fep->max_buf_size - ETH_HLEN - ETH_FCS_LEN;
 
 	ret = register_netdev(ndev);
 	if (ret)
-- 
2.43.0

On Thu,  4 Sep 2025 15:34:58 -0500 Shenwei Wang wrote:
> -#define	OPT_FRAME_SIZE	(PKT_MAXBUF_SIZE << 16)
> +#define	OPT_FRAME_SIZE	(fep->max_buf_size << 16)

Please don't implicitly depend on local variables with a certain name.
It's quite bad code hygiene. Looks like this define is only used once
so perhaps you should instead create a define like

#define OPT_ARCH_NEEDS_BUFSZ

And then use that in fec_restart() to either add

 (fep->max_buf_size << 16)

to rcntl or not?
-- 
pw-bot: cr

On Thu, Sep 04, 2025 at 03:34:58PM -0500, Shenwei Wang wrote:
> Refactor code to support Jumbo frame functionality by adding a member
> variable in the fec_enet_private structure to store PKT_MAXBUF_SIZE.
>
> Reviewed-by: Andrew Lunn <andrew@lunn.ch>
> Reviewed-by: Wei Fang <wei.fang@nxp.com>
> Signed-off-by: Shenwei Wang <shenwei.wang@nxp.com>

Reviewed-by: Frank Li <Frank.Li@nxp.com>

> ---
>  drivers/net/ethernet/freescale/fec.h      | 1 +
>  drivers/net/ethernet/freescale/fec_main.c | 9 +++++----
>  2 files changed, 6 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/net/ethernet/freescale/fec.h b/drivers/net/ethernet/freescale/fec.h
> index 5c8fdcef759b..2969088dda09 100644
> --- a/drivers/net/ethernet/freescale/fec.h
> +++ b/drivers/net/ethernet/freescale/fec.h
> @@ -619,6 +619,7 @@ struct fec_enet_private {
>
>  	unsigned int total_tx_ring_size;
>  	unsigned int total_rx_ring_size;
> +	unsigned int max_buf_size;
>
>  	struct	platform_device *pdev;
>
> diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c
> index 1383918f8a3f..5a21000aca59 100644
> --- a/drivers/net/ethernet/freescale/fec_main.c
> +++ b/drivers/net/ethernet/freescale/fec_main.c
> @@ -253,7 +253,7 @@ MODULE_PARM_DESC(macaddr, "FEC Ethernet MAC address");
>  #if defined(CONFIG_M523x) || defined(CONFIG_M527x) || defined(CONFIG_M528x) || \
>      defined(CONFIG_M520x) || defined(CONFIG_M532x) || defined(CONFIG_ARM) || \
>      defined(CONFIG_ARM64)
> -#define	OPT_FRAME_SIZE	(PKT_MAXBUF_SIZE << 16)
> +#define	OPT_FRAME_SIZE	(fep->max_buf_size << 16)
>  #else
>  #define	OPT_FRAME_SIZE	0
>  #endif
> @@ -1083,7 +1083,7 @@ static void fec_enet_enable_ring(struct net_device *ndev)
>  	for (i = 0; i < fep->num_rx_queues; i++) {
>  		rxq = fep->rx_queue[i];
>  		writel(rxq->bd.dma, fep->hwp + FEC_R_DES_START(i));
> -		writel(PKT_MAXBUF_SIZE, fep->hwp + FEC_R_BUFF_SIZE(i));
> +		writel(fep->max_buf_size, fep->hwp + FEC_R_BUFF_SIZE(i));
>
>  		/* enable DMA1/2 */
>  		if (i)
> @@ -1191,7 +1191,7 @@ fec_restart(struct net_device *ndev)
>  		else
>  			val &= ~FEC_RACC_OPTIONS;
>  		writel(val, fep->hwp + FEC_RACC);
> -		writel(PKT_MAXBUF_SIZE, fep->hwp + FEC_FTRL);
> +		writel(fep->max_buf_size, fep->hwp + FEC_FTRL);
>  	}
>  #endif
>
> @@ -4559,7 +4559,8 @@ fec_probe(struct platform_device *pdev)
>  	fec_enet_clk_enable(ndev, false);
>  	pinctrl_pm_select_sleep_state(&pdev->dev);
>
> -	ndev->max_mtu = PKT_MAXBUF_SIZE - ETH_HLEN - ETH_FCS_LEN;
> +	fep->max_buf_size = PKT_MAXBUF_SIZE;
> +	ndev->max_mtu = fep->max_buf_size - ETH_HLEN - ETH_FCS_LEN;
>
>  	ret = register_netdev(ndev);
>  	if (ret)
> --
> 2.43.0
>