MT7530/7531 has a global RX packet length register, which can be used
to set MTU.
Signed-off-by: DENG Qingfang <dqf...@gmail.com>
---
drivers/net/dsa/mt7530.c | 36 ++++++++++++++++++++++++++++++++++++
drivers/net/dsa/mt7530.h | 12 ++++++++++++
2 files changed, 48 insertions(+)
diff --git a/drivers/net/dsa/mt7530.c b/drivers/net/dsa/mt7530.c
index de7692b763d8..7764c66a47c9 100644
--- a/drivers/net/dsa/mt7530.c
+++ b/drivers/net/dsa/mt7530.c
@@ -1021,6 +1021,40 @@ mt7530_port_disable(struct dsa_switch *ds, int port)
mutex_unlock(&priv->reg_mutex);
}
+static int
+mt7530_port_change_mtu(struct dsa_switch *ds, int port, int new_mtu)
+{
+ struct mt7530_priv *priv = ds->priv;
+ int length;
+
+ /* When a new MTU is set, DSA always set the CPU port's MTU to the
largest MTU
+ * of the slave ports. Because the switch only has a global RX length
register,
+ * only allowing CPU port here is enough.
+ */
+ if (!dsa_is_cpu_port(ds, port))
+ return 0;
+
+ /* RX length also includes Ethernet header, MTK tag, and FCS length */
+ length = new_mtu + ETH_HLEN + MTK_HDR_LEN + ETH_FCS_LEN;
+ if (length <= 1522)
+ mt7530_rmw(priv, MT7530_GMACCR, MAX_RX_PKT_LEN_MASK,
MAX_RX_PKT_LEN_1522);
+ else if (length <= 1536)
+ mt7530_rmw(priv, MT7530_GMACCR, MAX_RX_PKT_LEN_MASK,
MAX_RX_PKT_LEN_1536);
+ else if (length <= 1552)
+ mt7530_rmw(priv, MT7530_GMACCR, MAX_RX_PKT_LEN_MASK,
MAX_RX_PKT_LEN_1552);
+ else
+ mt7530_rmw(priv, MT7530_GMACCR, MAX_RX_JUMBO_MASK |
MAX_RX_PKT_LEN_MASK,
+ MAX_RX_JUMBO(DIV_ROUND_UP(length, 1024)) |
MAX_RX_PKT_LEN_JUMBO);
+
+ return 0;
+}
+
+static int
+mt7530_port_max_mtu(struct dsa_switch *ds, int port)
+{
+ return MT7530_MAX_MTU;
+}
+
static void
mt7530_stp_state_set(struct dsa_switch *ds, int port, u8 state)
{
@@ -2519,6 +2553,8 @@ static const struct dsa_switch_ops mt7530_switch_ops = {
.get_sset_count = mt7530_get_sset_count,
.port_enable = mt7530_port_enable,
.port_disable = mt7530_port_disable,
+ .port_change_mtu = mt7530_port_change_mtu,
+ .port_max_mtu = mt7530_port_max_mtu,
.port_stp_state_set = mt7530_stp_state_set,
.port_bridge_join = mt7530_port_bridge_join,
.port_bridge_leave = mt7530_port_bridge_leave,
diff --git a/drivers/net/dsa/mt7530.h b/drivers/net/dsa/mt7530.h
index 9278a8e3d04e..77a6222d2635 100644
--- a/drivers/net/dsa/mt7530.h
+++ b/drivers/net/dsa/mt7530.h
@@ -11,6 +11,9 @@
#define MT7530_NUM_FDB_RECORDS 2048
#define MT7530_ALL_MEMBERS 0xff
+#define MTK_HDR_LEN 4
+#define MT7530_MAX_MTU (15 * 1024 - ETH_HLEN - ETH_FCS_LEN -
MTK_HDR_LEN)
+
enum mt753x_id {
ID_MT7530 = 0,
ID_MT7621 = 1,
@@ -289,6 +292,15 @@ enum mt7530_vlan_port_attr {
#define MT7531_DBG_CNT(x) (0x3018 + (x) * 0x100)
#define MT7531_DIS_CLR BIT(31)
+#define MT7530_GMACCR 0x30e0
+#define MAX_RX_JUMBO(x) ((x) << 2)
+#define MAX_RX_JUMBO_MASK GENMASK(5, 2)
+#define MAX_RX_PKT_LEN_MASK GENMASK(1, 0)
+#define MAX_RX_PKT_LEN_1522 0x0
+#define MAX_RX_PKT_LEN_1536 0x1
+#define MAX_RX_PKT_LEN_1552 0x2
+#define MAX_RX_PKT_LEN_JUMBO 0x3
+
/* Register for MIB */
#define MT7530_PORT_MIB_COUNTER(x) (0x4000 + (x) * 0x100)
#define MT7530_MIB_CCR 0x4fe0
--
2.25.1
