[PATCH net-next v20 08/10] net: dsa: mt7530: move MDIO bus locking into regmap
From: Christian Marangi <ansuelsmth@gmail.com>
Date: 2026-08-17 08:21:01
Also in:
linux-arm-kernel, linux-devicetree, linux-mediatek, lkml
Subsystem:
mediatek switch driver, networking drivers, networking [dsa], the rest · Maintainers:
Chester A. Unal, Daniel Golle, Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Andrew Lunn, Vladimir Oltean, Linus Torvalds
From: Daniel Golle <daniel@makrotopia.org>
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@makrotopia.org>
Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
---
drivers/net/dsa/mt7530-mdio.c | 9 ++++++---
drivers/net/dsa/mt7530.c | 36 ++++++-----------------------------
2 files changed, 12 insertions(+), 33 deletions(-)
diff --git a/drivers/net/dsa/mt7530-mdio.c b/drivers/net/dsa/mt7530-mdio.c
index 784dd58a7158..422f785d2143 100644
--- a/drivers/net/dsa/mt7530-mdio.c
+++ b/drivers/net/dsa/mt7530-mdio.c@@ -148,12 +148,14 @@ 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;
@@ -207,8 +209,9 @@ 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 2b7be091c056..d01772cfe3a2 100644
--- a/drivers/net/dsa/mt7530.c
+++ b/drivers/net/dsa/mt7530.c@@ -188,29 +188,13 @@ mt7530_mii_read(struct mt7530_priv *priv, u32 reg) static int mt7530_write(struct mt7530_priv *priv, u32 reg, u32 val) { - int ret; - - mt7530_mutex_lock(priv); - - ret = mt7530_mii_write(priv, reg, val); - - mt7530_mutex_unlock(priv); - - return ret; + return mt7530_mii_write(priv, reg, val); } 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
@@ -226,11 +210,7 @@ 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
@@ -597,7 +577,7 @@ 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; }
@@ -645,7 +625,7 @@ 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; }
@@ -681,7 +661,7 @@ 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; }
@@ -717,7 +697,7 @@ 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; }
@@ -1452,8 +1432,6 @@ 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;
@@ -1473,8 +1451,6 @@ 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; }
--
2.53.0