On Thu, Sep 04, 2025 at 03:35:00PM -0500, Shenwei Wang wrote:
> Add a new rx_frame_size member in the fec_enet_private structure to
> track the RX buffer size. On the Jumbo frame enabled system, the value
> will be recalculated whenever the MTU is updated, allowing the driver
> to allocate RX buffer efficiently.
>
> Configure the MAX_FL (Maximum Frame Length) based on the current MTU,
> by changing the OPT_FRAME_SIZE macro.
>
> Configure the TRUNC_FL (Frame Truncation Length) based on the smaller
> value between max_buf_size and the rx_frame_size to maintain consistent
> RX error behavior, regardless of whether Jumbo frames are enabled.
>
> 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 | 5 +++--
> 2 files changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/ethernet/freescale/fec.h b/drivers/net/ethernet/freescale/fec.h
> index 47317346b2f3..f1032a11aa76 100644
> --- a/drivers/net/ethernet/freescale/fec.h
> +++ b/drivers/net/ethernet/freescale/fec.h
> @@ -621,6 +621,7 @@ struct fec_enet_private {
> unsigned int total_rx_ring_size;
> unsigned int max_buf_size;
> unsigned int pagepool_order;
> + unsigned int rx_frame_size;
>
> struct platform_device *pdev;
>
> diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c
> index f046d32a62fb..cf5118838f9c 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 (fep->max_buf_size << 16)
> +#define OPT_FRAME_SIZE ((fep->netdev->mtu + ETH_HLEN + ETH_FCS_LEN) << 16)
> #else
> #define OPT_FRAME_SIZE 0
> #endif
> @@ -1191,7 +1191,7 @@ fec_restart(struct net_device *ndev)
> else
> val &= ~FEC_RACC_OPTIONS;
> writel(val, fep->hwp + FEC_RACC);
> - writel(fep->max_buf_size, fep->hwp + FEC_FTRL);
> + writel(min(fep->rx_frame_size, fep->max_buf_size), fep->hwp + FEC_FTRL);
> }
> #endif
>
> @@ -4560,6 +4560,7 @@ fec_probe(struct platform_device *pdev)
> pinctrl_pm_select_sleep_state(&pdev->dev);
>
> fep->pagepool_order = 0;
> + fep->rx_frame_size = FEC_ENET_RX_FRSIZE;
> fep->max_buf_size = PKT_MAXBUF_SIZE;
> ndev->max_mtu = fep->max_buf_size - ETH_HLEN - ETH_FCS_LEN;
>
> --
> 2.43.0
>