[PATCH net-next 01/10] net: dsa: microchip: split ksz8_change_mtu()
From: Bastien Curutchet
Date: Thu Jul 02 2026 - 05:23:28 EST
From: Vladimir Oltean <vladimir.oltean@xxxxxxx>
Even among the ksz8 family, there are big differences in the MTU change
procedure between KSZ87xx and KSZ88xx (KSZ8463 is like KSZ88xx here).
Since we have 3 separate dsa_switch_ops for what constitutes "KSZ8", we
can split those procedures into separate functions.
Signed-off-by: Vladimir Oltean <vladimir.oltean@xxxxxxx>
Signed-off-by: Bastien Curutchet (Schneider Electric) <bastien.curutchet@xxxxxxxxxxx>
---
drivers/net/dsa/microchip/ksz8.c | 49 ++++++++++++++++------------------------
1 file changed, 19 insertions(+), 30 deletions(-)
diff --git a/drivers/net/dsa/microchip/ksz8.c b/drivers/net/dsa/microchip/ksz8.c
index 586916570a84..c351179f6a60 100644
--- a/drivers/net/dsa/microchip/ksz8.c
+++ b/drivers/net/dsa/microchip/ksz8.c
@@ -158,10 +158,17 @@ static int ksz8_reset_switch(struct ksz_device *dev)
return 0;
}
-static int ksz8863_change_mtu(struct ksz_device *dev, int frame_size)
+static int ksz88xx_change_mtu(struct dsa_switch *ds, int port, int mtu)
{
+ struct ksz_device *dev = ds->priv;
+ int frame_size;
u8 ctrl2 = 0;
+ if (!dsa_is_cpu_port(dev->ds, port))
+ return 0;
+
+ frame_size = mtu + VLAN_ETH_HLEN + ETH_FCS_LEN;
+
if (frame_size <= KSZ8_LEGAL_PACKET_SIZE)
ctrl2 |= KSZ8863_LEGAL_PACKET_ENABLE;
else if (frame_size > KSZ8863_NORMAL_PACKET_SIZE)
@@ -171,11 +178,18 @@ static int ksz8863_change_mtu(struct ksz_device *dev, int frame_size)
KSZ8863_HUGE_PACKET_ENABLE, ctrl2);
}
-static int ksz8795_change_mtu(struct ksz_device *dev, int frame_size)
+static int ksz87xx_change_mtu(struct dsa_switch *ds, int port, int mtu)
{
+ struct ksz_device *dev = ds->priv;
u8 ctrl1 = 0, ctrl2 = 0;
+ u16 frame_size;
int ret;
+ if (!dsa_is_cpu_port(dev->ds, port))
+ return 0;
+
+ frame_size = mtu + VLAN_ETH_HLEN + ETH_FCS_LEN;
+
if (frame_size > KSZ8_LEGAL_PACKET_SIZE)
ctrl2 |= SW_LEGAL_PACKET_DISABLE;
if (frame_size > KSZ8863_NORMAL_PACKET_SIZE)
@@ -188,31 +202,6 @@ static int ksz8795_change_mtu(struct ksz_device *dev, int frame_size)
return ksz_rmw8(dev, REG_SW_CTRL_2, SW_LEGAL_PACKET_DISABLE, ctrl2);
}
-static int ksz8_change_mtu(struct dsa_switch *ds, int port, int mtu)
-{
- struct ksz_device *dev = ds->priv;
- u16 frame_size;
-
- if (!dsa_is_cpu_port(dev->ds, port))
- return 0;
-
- frame_size = mtu + VLAN_ETH_HLEN + ETH_FCS_LEN;
-
- switch (dev->chip_id) {
- case KSZ8795_CHIP_ID:
- case KSZ8794_CHIP_ID:
- case KSZ8765_CHIP_ID:
- return ksz8795_change_mtu(dev, frame_size);
- case KSZ8463_CHIP_ID:
- case KSZ88X3_CHIP_ID:
- case KSZ8864_CHIP_ID:
- case KSZ8895_CHIP_ID:
- return ksz8863_change_mtu(dev, frame_size);
- }
-
- return -EOPNOTSUPP;
-}
-
static int ksz8_port_queue_split(struct ksz_device *dev, int port, int queues)
{
u8 mask_4q, mask_2q;
@@ -2551,7 +2540,7 @@ const struct dsa_switch_ops ksz8463_switch_ops = {
.port_mirror_del = ksz8_port_mirror_del,
.get_stats64 = ksz_get_stats64,
.get_pause_stats = ksz_get_pause_stats,
- .port_change_mtu = ksz8_change_mtu,
+ .port_change_mtu = ksz88xx_change_mtu,
.port_max_mtu = ksz_max_mtu,
.suspend = ksz_suspend,
.resume = ksz_resume,
@@ -2601,7 +2590,7 @@ const struct dsa_switch_ops ksz87xx_switch_ops = {
.port_mirror_del = ksz8_port_mirror_del,
.get_stats64 = ksz_get_stats64,
.get_pause_stats = ksz_get_pause_stats,
- .port_change_mtu = ksz8_change_mtu,
+ .port_change_mtu = ksz87xx_change_mtu,
.port_max_mtu = ksz_max_mtu,
.suspend = ksz_suspend,
.resume = ksz_resume,
@@ -2652,7 +2641,7 @@ const struct dsa_switch_ops ksz88xx_switch_ops = {
.port_mirror_del = ksz8_port_mirror_del,
.get_stats64 = ksz_get_stats64,
.get_pause_stats = ksz_get_pause_stats,
- .port_change_mtu = ksz8_change_mtu,
+ .port_change_mtu = ksz88xx_change_mtu,
.port_max_mtu = ksz_max_mtu,
.get_wol = ksz_get_wol,
.set_wol = ksz_set_wol,
--
2.54.0