[PATCH net 3/4] net: dsa: mt7530: error out on failed PHY_IAC command writes
From: Daniel Golle <daniel@makrotopia.org>
Date: 2026-07-30 16:03:48
Also in:
linux-mediatek, lkml, netdev
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
MT7531_PHY_ACS_ST is only ever set by the command write that precedes
each poll in the MT7531 indirect PHY access functions, and that
write's return value is discarded. A failed write leaves ACS_ST at 0
from the previous access, so the poll succeeds on its first iteration
and the functions return stale IAC contents as if they were fresh PHY
data. Check the writes and bail out before polling.
Fixes: c288575f7810 ("net: dsa: mt7530: Add the support of MT7531 switch")
Signed-off-by: Daniel Golle <daniel@makrotopia.org>
---
drivers/net/dsa/mt7530.c | 24 ++++++++++++++++++------
1 file changed, 18 insertions(+), 6 deletions(-)
diff --git a/drivers/net/dsa/mt7530.c b/drivers/net/dsa/mt7530.c
index 9be6fb63c311..2a17696e6a45 100644
--- a/drivers/net/dsa/mt7530.c
+++ b/drivers/net/dsa/mt7530.c@@ -565,7 +565,9 @@ mt7531_ind_c45_phy_read(struct mt7530_priv *priv, int port, int devad, reg = MT7531_MDIO_CL45_ADDR | MT7531_MDIO_PHY_ADDR(port) | MT7531_MDIO_DEV_ADDR(devad) | regnum; - mt7530_mii_write(priv, MT7531_PHY_IAC, reg | MT7531_PHY_ACS_ST); + ret = mt7530_mii_write(priv, MT7531_PHY_IAC, reg | MT7531_PHY_ACS_ST); + if (ret < 0) + goto out; ret = regmap_read_poll_timeout(priv->regmap, MT7531_PHY_IAC, val, !(val & MT7531_PHY_ACS_ST), 20, 100000);
@@ -576,7 +578,9 @@ mt7531_ind_c45_phy_read(struct mt7530_priv *priv, int port, int devad, reg = MT7531_MDIO_CL45_READ | MT7531_MDIO_PHY_ADDR(port) | MT7531_MDIO_DEV_ADDR(devad); - mt7530_mii_write(priv, MT7531_PHY_IAC, reg | MT7531_PHY_ACS_ST); + ret = mt7530_mii_write(priv, MT7531_PHY_IAC, reg | MT7531_PHY_ACS_ST); + if (ret < 0) + goto out; ret = regmap_read_poll_timeout(priv->regmap, MT7531_PHY_IAC, val, !(val & MT7531_PHY_ACS_ST), 20, 100000);
@@ -610,7 +614,9 @@ mt7531_ind_c45_phy_write(struct mt7530_priv *priv, int port, int devad, reg = MT7531_MDIO_CL45_ADDR | MT7531_MDIO_PHY_ADDR(port) | MT7531_MDIO_DEV_ADDR(devad) | regnum; - mt7530_mii_write(priv, MT7531_PHY_IAC, reg | MT7531_PHY_ACS_ST); + ret = mt7530_mii_write(priv, MT7531_PHY_IAC, reg | MT7531_PHY_ACS_ST); + if (ret < 0) + goto out; ret = regmap_read_poll_timeout(priv->regmap, MT7531_PHY_IAC, val, !(val & MT7531_PHY_ACS_ST), 20, 100000);
@@ -621,7 +627,9 @@ mt7531_ind_c45_phy_write(struct mt7530_priv *priv, int port, int devad, reg = MT7531_MDIO_CL45_WRITE | MT7531_MDIO_PHY_ADDR(port) | MT7531_MDIO_DEV_ADDR(devad) | data; - mt7530_mii_write(priv, MT7531_PHY_IAC, reg | MT7531_PHY_ACS_ST); + ret = mt7530_mii_write(priv, MT7531_PHY_IAC, reg | MT7531_PHY_ACS_ST); + if (ret < 0) + goto out; ret = regmap_read_poll_timeout(priv->regmap, MT7531_PHY_IAC, val, !(val & MT7531_PHY_ACS_ST), 20, 100000);
@@ -654,7 +662,9 @@ mt7531_ind_c22_phy_read(struct mt7530_priv *priv, int port, int regnum) val = MT7531_MDIO_CL22_READ | MT7531_MDIO_PHY_ADDR(port) | MT7531_MDIO_REG_ADDR(regnum); - mt7530_mii_write(priv, MT7531_PHY_IAC, val | MT7531_PHY_ACS_ST); + ret = mt7530_mii_write(priv, MT7531_PHY_IAC, val | MT7531_PHY_ACS_ST); + if (ret < 0) + goto out; ret = regmap_read_poll_timeout(priv->regmap, MT7531_PHY_IAC, val, !(val & MT7531_PHY_ACS_ST), 20, 100000);
@@ -689,7 +699,9 @@ mt7531_ind_c22_phy_write(struct mt7530_priv *priv, int port, int regnum, reg = MT7531_MDIO_CL22_WRITE | MT7531_MDIO_PHY_ADDR(port) | MT7531_MDIO_REG_ADDR(regnum) | data; - mt7530_mii_write(priv, MT7531_PHY_IAC, reg | MT7531_PHY_ACS_ST); + ret = mt7530_mii_write(priv, MT7531_PHY_IAC, reg | MT7531_PHY_ACS_ST); + if (ret < 0) + goto out; ret = regmap_read_poll_timeout(priv->regmap, MT7531_PHY_IAC, reg, !(reg & MT7531_PHY_ACS_ST), 20, 100000);
--
2.55.0