[PATCH net-next v2 1/8] net: dsa: mt7530: move MDIO bus locking into regmap
Daniel Golle
daniel at makrotopia.org
Fri Jun 12 18:10:57 PDT 2026
The switch register regmap was created with .disable_locking = true,
relying on callers to manually lock the MDIO bus. Move the locking
into the regmap using .lock/.unlock callbacks, matching the PCS
regmaps that already do this. This allows any code path reaching the
regmap to be automatically protected.
With regmap handling bus locking, the manual mt7530_mutex_lock/unlock
wrappers in mt7530_write(), _mt7530_read(), mt7530_rmw() and
mt7530_port_change_mtu() become redundant and are removed.
The MT7531 indirect PHY access functions need serialization of their
multi-step register sequences, but no longer need to hold bus->mdio_lock
across the whole operation. Switch them to reg_mutex.
core_write()/core_rmw() are the only remaining callers of
mt7530_mutex_lock(). They access TRGMII core PHY registers via the
clause 22 MMD indirect protocol -- a separate register space that
bypasses regmap and needs manual bus->mdio_lock protection.
Generated using the following semantic patch:
// Remove mt7530_mutex_lock/unlock around single regmap-based calls.
@@
expression priv, reg, val;
@@
{
- mt7530_mutex_lock(priv);
-
mt7530_mii_write(priv, reg, val);
-
- mt7530_mutex_unlock(priv);
}
@@
expression priv, reg, mask, set;
@@
{
- mt7530_mutex_lock(priv);
-
regmap_update_bits(priv->regmap, reg, mask, set);
-
- mt7530_mutex_unlock(priv);
}
@@
expression p;
identifier val;
@@
{
- u32 val;
- mt7530_mutex_lock(p->priv);
- val = mt7530_mii_read(p->priv, p->reg);
- mt7530_mutex_unlock(p->priv);
- return val;
+ return mt7530_mii_read(p->priv, p->reg);
}
@@
expression priv;
@@
- mt7530_mutex_lock(priv);
val = mt7530_mii_read(priv, MT7530_GMACCR);
...
mt7530_mii_write(priv, MT7530_GMACCR, val);
- mt7530_mutex_unlock(priv);
@@
expression priv, port;
@@
INIT_MT7530_DUMMY_POLL(&p, priv, MT7531_PHY_IAC);
- mt7530_mutex_lock(priv);
+ mutex_lock(&priv->reg_mutex);
@@
expression priv;
@@
out:
- mt7530_mutex_unlock(priv);
+ mutex_unlock(&priv->reg_mutex);
Signed-off-by: Daniel Golle <daniel at makrotopia.org>
---
v2: no changes
drivers/net/dsa/mt7530-mdio.c | 9 ++++++---
drivers/net/dsa/mt7530.c | 38 +++++++++--------------------------
2 files changed, 15 insertions(+), 32 deletions(-)
diff --git a/drivers/net/dsa/mt7530-mdio.c b/drivers/net/dsa/mt7530-mdio.c
index 11ea924a9f35..f7c8eeb27211 100644
--- a/drivers/net/dsa/mt7530-mdio.c
+++ b/drivers/net/dsa/mt7530-mdio.c
@@ -141,12 +141,14 @@ static const struct regmap_config regmap_config = {
.val_bits = 32,
.reg_stride = 4,
.max_register = MT7530_CREV,
- .disable_locking = true,
+ .lock = mt7530_mdio_regmap_lock,
+ .unlock = mt7530_mdio_regmap_unlock,
};
static int
mt7530_probe(struct mdio_device *mdiodev)
{
+ struct regmap_config rc = regmap_config;
struct mt7530_priv *priv;
struct device_node *dn;
int ret;
@@ -200,8 +202,9 @@ mt7530_probe(struct mdio_device *mdiodev)
return PTR_ERR(priv->io_pwr);
}
- priv->regmap = devm_regmap_init(priv->dev, &mt7530_regmap_bus, priv,
- ®map_config);
+ rc.lock_arg = &priv->bus->mdio_lock;
+ priv->regmap = devm_regmap_init(priv->dev, &mt7530_regmap_bus,
+ priv, &rc);
if (IS_ERR(priv->regmap))
return PTR_ERR(priv->regmap);
diff --git a/drivers/net/dsa/mt7530.c b/drivers/net/dsa/mt7530.c
index 3c2a3029b10c..5f56a423b147 100644
--- a/drivers/net/dsa/mt7530.c
+++ b/drivers/net/dsa/mt7530.c
@@ -184,11 +184,7 @@ mt7530_mii_read(struct mt7530_priv *priv, u32 reg)
static void
mt7530_write(struct mt7530_priv *priv, u32 reg, u32 val)
{
- mt7530_mutex_lock(priv);
-
mt7530_mii_write(priv, reg, val);
-
- mt7530_mutex_unlock(priv);
}
static u32
@@ -200,15 +196,7 @@ _mt7530_unlocked_read(struct mt7530_dummy_poll *p)
static u32
_mt7530_read(struct mt7530_dummy_poll *p)
{
- u32 val;
-
- mt7530_mutex_lock(p->priv);
-
- val = mt7530_mii_read(p->priv, p->reg);
-
- mt7530_mutex_unlock(p->priv);
-
- return val;
+ return mt7530_mii_read(p->priv, p->reg);
}
static u32
@@ -224,11 +212,7 @@ static void
mt7530_rmw(struct mt7530_priv *priv, u32 reg,
u32 mask, u32 set)
{
- mt7530_mutex_lock(priv);
-
regmap_update_bits(priv->regmap, reg, mask, set);
-
- mt7530_mutex_unlock(priv);
}
static void
@@ -555,7 +539,7 @@ mt7531_ind_c45_phy_read(struct mt7530_priv *priv, int port, int devad,
INIT_MT7530_DUMMY_POLL(&p, priv, MT7531_PHY_IAC);
- mt7530_mutex_lock(priv);
+ mutex_lock(&priv->reg_mutex);
ret = readx_poll_timeout(_mt7530_unlocked_read, &p, val,
!(val & MT7531_PHY_ACS_ST), 20, 100000);
@@ -588,7 +572,7 @@ mt7531_ind_c45_phy_read(struct mt7530_priv *priv, int port, int devad,
ret = val & MT7531_MDIO_RW_DATA_MASK;
out:
- mt7530_mutex_unlock(priv);
+ mutex_unlock(&priv->reg_mutex);
return ret;
}
@@ -603,7 +587,7 @@ mt7531_ind_c45_phy_write(struct mt7530_priv *priv, int port, int devad,
INIT_MT7530_DUMMY_POLL(&p, priv, MT7531_PHY_IAC);
- mt7530_mutex_lock(priv);
+ mutex_lock(&priv->reg_mutex);
ret = readx_poll_timeout(_mt7530_unlocked_read, &p, val,
!(val & MT7531_PHY_ACS_ST), 20, 100000);
@@ -635,7 +619,7 @@ mt7531_ind_c45_phy_write(struct mt7530_priv *priv, int port, int devad,
}
out:
- mt7530_mutex_unlock(priv);
+ mutex_unlock(&priv->reg_mutex);
return ret;
}
@@ -649,7 +633,7 @@ mt7531_ind_c22_phy_read(struct mt7530_priv *priv, int port, int regnum)
INIT_MT7530_DUMMY_POLL(&p, priv, MT7531_PHY_IAC);
- mt7530_mutex_lock(priv);
+ mutex_lock(&priv->reg_mutex);
ret = readx_poll_timeout(_mt7530_unlocked_read, &p, val,
!(val & MT7531_PHY_ACS_ST), 20, 100000);
@@ -672,7 +656,7 @@ mt7531_ind_c22_phy_read(struct mt7530_priv *priv, int port, int regnum)
ret = val & MT7531_MDIO_RW_DATA_MASK;
out:
- mt7530_mutex_unlock(priv);
+ mutex_unlock(&priv->reg_mutex);
return ret;
}
@@ -687,7 +671,7 @@ mt7531_ind_c22_phy_write(struct mt7530_priv *priv, int port, int regnum,
INIT_MT7530_DUMMY_POLL(&p, priv, MT7531_PHY_IAC);
- mt7530_mutex_lock(priv);
+ mutex_lock(&priv->reg_mutex);
ret = readx_poll_timeout(_mt7530_unlocked_read, &p, reg,
!(reg & MT7531_PHY_ACS_ST), 20, 100000);
@@ -709,7 +693,7 @@ mt7531_ind_c22_phy_write(struct mt7530_priv *priv, int port, int regnum,
}
out:
- mt7530_mutex_unlock(priv);
+ mutex_unlock(&priv->reg_mutex);
return ret;
}
@@ -1444,8 +1428,6 @@ mt7530_port_change_mtu(struct dsa_switch *ds, int port, int new_mtu)
if (!dsa_is_cpu_port(ds, port))
return 0;
- mt7530_mutex_lock(priv);
-
val = mt7530_mii_read(priv, MT7530_GMACCR);
val &= ~MAX_RX_PKT_LEN_MASK;
@@ -1465,8 +1447,6 @@ mt7530_port_change_mtu(struct dsa_switch *ds, int port, int new_mtu)
mt7530_mii_write(priv, MT7530_GMACCR, val);
- mt7530_mutex_unlock(priv);
-
return 0;
}
--
2.54.0
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