diff --git a/drivers/net/ethernet/spacemit/k1_emac.c b/drivers/net/ethernet/spacemit/k1_emac.c
index 88e9424d2d51..b49c4708bf9e 100644
--- a/drivers/net/ethernet/spacemit/k1_emac.c
+++ b/drivers/net/ethernet/spacemit/k1_emac.c
@@ -12,6 +12,7 @@
 #include <linux/dma-mapping.h>
 #include <linux/etherdevice.h>
 #include <linux/ethtool.h>
+#include <linux/if_vlan.h>
 #include <linux/interrupt.h>
 #include <linux/io.h>
 #include <linux/iopoll.h>
@@ -38,7 +39,7 @@
 
 #define EMAC_DEFAULT_BUFSIZE		1536
 #define EMAC_RX_BUF_2K			2048
-#define EMAC_RX_BUF_4K			4096
+#define EMAC_RX_BUF_MAX			FIELD_MAX(RX_DESC_1_BUFFER_SIZE_1_MASK)
 
 /* Tuning parameters from SpacemiT */
 #define EMAC_TX_FRAMES			64
@@ -202,8 +203,7 @@ static void emac_init_hw(struct emac_priv *priv)
 {
 	/* Destination address for 802.3x Ethernet flow control */
 	u8 fc_dest_addr[ETH_ALEN] = { 0x01, 0x80, 0xc2, 0x00, 0x00, 0x01 };
-
-	u32 rxirq = 0, dma = 0;
+	u32 rxirq = 0, dma = 0, frame_sz;
 
 	regmap_set_bits(priv->regmap_apmu,
 			priv->regmap_apmu_offset + APMU_EMAC_CTRL_REG,
@@ -228,6 +228,15 @@ static void emac_init_hw(struct emac_priv *priv)
 		DEFAULT_TX_THRESHOLD);
 	emac_wr(priv, MAC_RECEIVE_PACKET_START_THRESHOLD, DEFAULT_RX_THRESHOLD);
 
+	/* Set maximum frame size and jabber size based on configured MTU,
+	 * accounting for Ethernet header, double VLAN tags, and FCS.
+	 */
+	frame_sz = priv->ndev->mtu + ETH_HLEN + 2 * VLAN_HLEN + ETH_FCS_LEN;
+
+	emac_wr(priv, MAC_MAXIMUM_FRAME_SIZE, frame_sz);
+	emac_wr(priv, MAC_TRANSMIT_JABBER_SIZE, frame_sz);
+	emac_wr(priv, MAC_RECEIVE_JABBER_SIZE, frame_sz);
+
 	/* Configure flow control (enabled in emac_adjust_link() later) */
 	emac_set_mac_addr_reg(priv, fc_dest_addr, MAC_FC_SOURCE_ADDRESS_HIGH);
 	emac_wr(priv, MAC_FC_PAUSE_HIGH_THRESHOLD, DEFAULT_FC_FIFO_HIGH);
@@ -924,14 +933,14 @@ static int emac_change_mtu(struct net_device *ndev, int mtu)
 		return -EBUSY;
 	}
 
-	frame_len = mtu + ETH_HLEN + ETH_FCS_LEN;
+	frame_len = mtu + ETH_HLEN + 2 * VLAN_HLEN + ETH_FCS_LEN;
 
 	if (frame_len <= EMAC_DEFAULT_BUFSIZE)
 		priv->dma_buf_sz = EMAC_DEFAULT_BUFSIZE;
 	else if (frame_len <= EMAC_RX_BUF_2K)
 		priv->dma_buf_sz = EMAC_RX_BUF_2K;
 	else
-		priv->dma_buf_sz = EMAC_RX_BUF_4K;
+		priv->dma_buf_sz = EMAC_RX_BUF_MAX;
 
 	ndev->mtu = mtu;
 
@@ -2025,7 +2034,7 @@ static int emac_probe(struct platform_device *pdev)
 	ndev->hw_features = NETIF_F_SG;
 	ndev->features |= ndev->hw_features;
 
-	ndev->max_mtu = EMAC_RX_BUF_4K - (ETH_HLEN + ETH_FCS_LEN);
+	ndev->max_mtu = EMAC_RX_BUF_MAX - (ETH_HLEN + 2 * VLAN_HLEN + ETH_FCS_LEN);
 	ndev->pcpu_stat_type = NETDEV_PCPU_STAT_DSTATS;
 
 	priv = netdev_priv(ndev);