net: fec: update MAX_FL based on the current MTU

Configure the MAX_FL (Maximum Frame Length) register according to the
current MTU value, which ensures that packets exceeding the configured MTU
trigger an RX error.

Reviewed-by: Wei Fang <wei.fang@nxp.com>
Signed-off-by: Shenwei Wang <shenwei.wang@nxp.com>
Link: https://patch.msgid.link/20250910185211.721341-4-shenwei.wang@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c
index 05feffc4162be51595c9d799b0d025055f6e9f58..7bc1fe2c13ed605f3811663a38962365592339ad 100644 (file)
--- a/drivers/net/ethernet/freescale/fec_main.c
+++ b/drivers/net/ethernet/freescale/fec_main.c
@@ -1149,7 +1149,7 @@ fec_restart(struct net_device *ndev)
        u32 rcntl = FEC_RCR_MII;
 
        if (OPT_ARCH_HAS_MAX_FL)
-               rcntl |= fep->max_buf_size << 16;
+               rcntl |= (fep->netdev->mtu + ETH_HLEN + ETH_FCS_LEN) << 16;
 
        if (fep->bufdesc_ex)
                fec_ptp_save_state(fep);