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authorDENG Qingfang <dqfext@gmail.com>2020-11-03 13:06:18 +0800
committerJakub Kicinski <kuba@kernel.org>2020-11-04 16:48:11 -0800
commit9470174e7581e75a8ebd78964997314dfc2e706c (patch)
treeef2a37991f30e1f052651d653267eb540cb1bbec /drivers/net/dsa/mt7530.c
parent2c24eefb2462617d264398f91e75cc0fdc978e4f (diff)
net: dsa: mt7530: support setting MTU
MT7530/7531 has a global RX packet length register, which can be used to set MTU. Supported packet length values are 1522 (1518 if untagged), 1536, 1552, and multiple of 1024 (from 2048 to 15360). Signed-off-by: DENG Qingfang <dqfext@gmail.com> Link: https://lore.kernel.org/r/20201103050618.11419-1-dqfext@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'drivers/net/dsa/mt7530.c')
-rw-r--r--drivers/net/dsa/mt7530.c49
1 files changed, 49 insertions, 0 deletions
diff --git a/drivers/net/dsa/mt7530.c b/drivers/net/dsa/mt7530.c
index 771f58f50d61..6408402a44f5 100644
--- a/drivers/net/dsa/mt7530.c
+++ b/drivers/net/dsa/mt7530.c
@@ -1021,6 +1021,53 @@ 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;
+ struct mii_bus *bus = priv->bus;
+ int length;
+ u32 val;
+
+ /* 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;
+
+ mutex_lock_nested(&bus->mdio_lock, MDIO_MUTEX_NESTED);
+
+ val = mt7530_mii_read(priv, MT7530_GMACCR);
+ val &= ~MAX_RX_PKT_LEN_MASK;
+
+ /* 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) {
+ val |= MAX_RX_PKT_LEN_1522;
+ } else if (length <= 1536) {
+ val |= MAX_RX_PKT_LEN_1536;
+ } else if (length <= 1552) {
+ val |= MAX_RX_PKT_LEN_1552;
+ } else {
+ val &= ~MAX_RX_JUMBO_MASK;
+ val |= MAX_RX_JUMBO(DIV_ROUND_UP(length, 1024));
+ val |= MAX_RX_PKT_LEN_JUMBO;
+ }
+
+ mt7530_mii_write(priv, MT7530_GMACCR, val);
+
+ mutex_unlock(&bus->mdio_lock);
+
+ 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 +2566,8 @@ 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,