[PATCH v2] net: dsa: qca8k: fix kernel panic with legacy mdio mapping

From: Ansuel Smith
Date: Sat Sep 11 2021 - 11:50:30 EST


When the mdio legacy mapping is used the mii_bus priv registered by DSA
refer to the dsa switch struct instead of the qca8k_priv struct and
causes a kernel panic. Create dedicated function when the internal
dedicated mdio driver is used to properly handle the 2 different
implementation.

Fixes: 759bafb8a322 ("net: dsa: qca8k: add support for internal phy and internal mdio")
Signed-off-by: Ansuel Smith <ansuelsmth@xxxxxxxxx>
---
drivers/net/dsa/qca8k.c | 30 ++++++++++++++++++++++--------
1 file changed, 22 insertions(+), 8 deletions(-)

diff --git a/drivers/net/dsa/qca8k.c b/drivers/net/dsa/qca8k.c
index 1f63f50f73f1..bda5a9bf4f52 100644
--- a/drivers/net/dsa/qca8k.c
+++ b/drivers/net/dsa/qca8k.c
@@ -643,10 +643,8 @@ qca8k_mdio_busy_wait(struct mii_bus *bus, u32 reg, u32 mask)
}

static int
-qca8k_mdio_write(struct mii_bus *salve_bus, int phy, int regnum, u16 data)
+qca8k_mdio_write(struct mii_bus *bus, int phy, int regnum, u16 data)
{
- struct qca8k_priv *priv = salve_bus->priv;
- struct mii_bus *bus = priv->bus;
u16 r1, r2, page;
u32 val;
int ret;
@@ -682,10 +680,8 @@ qca8k_mdio_write(struct mii_bus *salve_bus, int phy, int regnum, u16 data)
}

static int
-qca8k_mdio_read(struct mii_bus *salve_bus, int phy, int regnum)
+qca8k_mdio_read(struct mii_bus *bus, int phy, int regnum)
{
- struct qca8k_priv *priv = salve_bus->priv;
- struct mii_bus *bus = priv->bus;
u16 r1, r2, page;
u32 val;
int ret;
@@ -726,6 +722,24 @@ qca8k_mdio_read(struct mii_bus *salve_bus, int phy, int regnum)
return ret;
}

+static int
+qca8k_internal_mdio_write(struct mii_bus *slave_bus, int phy, int regnum, u16 data)
+{
+ struct qca8k_priv *priv = slave_bus->priv;
+ struct mii_bus *bus = priv->bus;
+
+ return qca8k_mdio_write(bus, phy, regnum, data);
+}
+
+static int
+qca8k_internal_mdio_read(struct mii_bus *slave_bus, int phy, int regnum)
+{
+ struct qca8k_priv *priv = slave_bus->priv;
+ struct mii_bus *bus = priv->bus;
+
+ return qca8k_mdio_read(bus, phy, regnum);
+}
+
static int
qca8k_phy_write(struct dsa_switch *ds, int port, int regnum, u16 data)
{
@@ -775,8 +789,8 @@ qca8k_mdio_register(struct qca8k_priv *priv, struct device_node *mdio)

bus->priv = (void *)priv;
bus->name = "qca8k slave mii";
- bus->read = qca8k_mdio_read;
- bus->write = qca8k_mdio_write;
+ bus->read = qca8k_internal_mdio_read;
+ bus->write = qca8k_internal_mdio_write;
snprintf(bus->id, MII_BUS_ID_SIZE, "qca8k-%d",
ds->index);

--
2.32.0