Merge branch 'net-dsa-mt7530-fix-remaining-swallowed-mdio-access-errors'

Daniel Golle says:

====================
net: dsa: mt7530: fix remaining swallowed MDIO access errors

The original series, "net: dsa: mt7530: fix swallowed MDIO read
errors", landed on net as its v1 [1] just before its v2 [2] was sent.
This series started from the fixes in that original v2 which its v1
had not already carried: the two standalone patches that original v2
grew from the Sashiko AI review of its v1 (the mtk-lynxi read check
and the regmap IRQ serialization), plus, split into patches of their
own, the companion fixes original v2 had folded into the
already-applied patches -- the unchecked bus->read() in core_rmw() and
the unchecked PHY_IAC command writes in the MT7531 indirect PHY access
functions.

The Sashiko AI review of this series' own v1 [3] then flagged two more
swallowed MDIO errors of the same kind, added here as patches of their
own: the unchecked CORE_PLL_GROUP4 read-modify-write in mt7531_setup(),
and the unchecked ATC/VTCR command-register writes in mt7530_fdb_cmd()
and mt7530_vlan_cmd().

The remaining non-fix changes from the original v2, dropping a
redundant read-back and improving the poll failure messages, will
follow via net-next.

[1] https://lore.kernel.org/netdev/cover.1785213071.git.daniel@makrotopia.org/
[2] https://lore.kernel.org/netdev/cover.1785368701.git.daniel@makrotopia.org/
[3] https://lore.kernel.org/netdev/cover.1785427248.git.daniel@makrotopia.org/
====================

Link: https://patch.msgid.link/cover.1785811140.git.daniel@makrotopia.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

2 files changed, 75 insertions, 18 deletions

diff --git a/drivers/net/dsa/mt7530.c b/drivers/net/dsa/mt7530.c
index 55131bfd11f6..2b7be091c056 100644
--- a/drivers/net/dsa/mt7530.c
+++ b/drivers/net/dsa/mt7530.c
@@ -124,8 +124,12 @@ core_rmw(struct mt7530_priv *priv, u32 reg, u32 mask, u32 set)
 		goto err;
 
 	/* Read the content of the MMD's selected register */
-	val = bus->read(bus, MT753X_CTRL_PHY_ADDR(priv->mdiodev->addr),
+	ret = bus->read(bus, MT753X_CTRL_PHY_ADDR(priv->mdiodev->addr),
 			MII_MMD_DATA);
+	if (ret < 0)
+		goto err;
+	val = ret;
+
 	val &= ~mask;
 	val |= set;
 	/* Write the data into MMD's selected register */
@@ -181,14 +185,18 @@ mt7530_mii_read(struct mt7530_priv *priv, u32 reg)
 	return val;
 }
 
-static void
+static int
 mt7530_write(struct mt7530_priv *priv, u32 reg, u32 val)
 {
+	int ret;
+
 	mt7530_mutex_lock(priv);
 
-	mt7530_mii_write(priv, reg, val);
+	ret = mt7530_mii_write(priv, reg, val);
 
 	mt7530_mutex_unlock(priv);
+
+	return ret;
 }
 
 static u32
@@ -245,7 +253,9 @@ mt7530_fdb_cmd(struct mt7530_priv *priv, enum mt7530_fdb_cmd cmd, u32 *rsp)
 
 	/* Set the command operating upon the MAC address entries */
 	val = ATC_BUSY | ATC_MAT(0) | cmd;
-	mt7530_write(priv, MT7530_ATC, val);
+	ret = mt7530_write(priv, MT7530_ATC, val);
+	if (ret)
+		return ret;
 
 	mt7530_mutex_lock(priv);
 
@@ -561,7 +571,9 @@ 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);
@@ -572,7 +584,9 @@ 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);
@@ -606,7 +620,9 @@ 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);
@@ -617,7 +633,9 @@ 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);
@@ -650,7 +668,9 @@ 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);
@@ -685,7 +705,9 @@ 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);
@@ -1616,7 +1638,9 @@ mt7530_vlan_cmd(struct mt7530_priv *priv, enum mt7530_vlan_cmd cmd, u16 vid)
 	int ret;
 
 	val = VTCR_BUSY | VTCR_FUNC(cmd) | vid;
-	mt7530_write(priv, MT7530_VTCR, val);
+	ret = mt7530_write(priv, MT7530_VTCR, val);
+	if (ret)
+		return ret;
 
 	mt7530_mutex_lock(priv);
 
@@ -2295,6 +2319,21 @@ static const struct regmap_irq mt7530_irqs[] = {
 	REGMAP_IRQ_REG_LINE(31, 32), /* ACL */
 };
 
+/* Serialize regmap-irq's mask sync like every other regmap user */
+static int mt7530_irq_mask_sync(int index, unsigned int mask_buf_def,
+				unsigned int mask_buf, void *irq_drv_data)
+{
+	struct mt7530_priv *priv = irq_drv_data;
+	int ret;
+
+	mt7530_mutex_lock(priv);
+	ret = regmap_update_bits(priv->regmap, MT7530_SYS_INT_EN,
+				 mask_buf_def, ~mask_buf);
+	mt7530_mutex_unlock(priv);
+
+	return ret;
+}
+
 static const struct regmap_irq_chip mt7530_regmap_irq_chip = {
 	.name = KBUILD_MODNAME,
 	.status_base = MT7530_SYS_INT_STS,
@@ -2304,12 +2343,14 @@ static const struct regmap_irq_chip mt7530_regmap_irq_chip = {
 	.irqs = mt7530_irqs,
 	.num_irqs = ARRAY_SIZE(mt7530_irqs),
 	.num_regs = 1,
+	.handle_mask_sync = mt7530_irq_mask_sync,
 };
 
 static int
 mt7530_setup_irq(struct mt7530_priv *priv)
 {
 	struct regmap_irq_chip_data *irq_data;
+	struct regmap_irq_chip *chip;
 	struct device *dev = priv->dev;
 	struct device_node *np = dev->of_node;
 	int irq, ret;
@@ -2329,10 +2370,17 @@ mt7530_setup_irq(struct mt7530_priv *priv)
 	if (priv->id == ID_MT7530 || priv->id == ID_MT7621)
 		mt7530_set(priv, MT7530_TOP_SIG_CTRL, TOP_SIG_CTRL_NORMAL);
 
+	chip = devm_kmemdup(dev, &mt7530_regmap_irq_chip, sizeof(*chip),
+			    GFP_KERNEL);
+	if (!chip)
+		return -ENOMEM;
+
+	chip->irq_drv_data = priv;
+
 	ret = devm_regmap_add_irq_chip_fwnode(dev, dev_fwnode(dev),
 					      priv->regmap, irq,
 					      IRQF_ONESHOT,
-					      0, &mt7530_regmap_irq_chip,
+					      0, chip,
 					      &irq_data);
 	if (ret)
 		return ret;
@@ -2765,14 +2813,20 @@ mt7531_setup(struct dsa_switch *ds)
 	 * phy_[read,write]_mmd_indirect is called, we provide our own
 	 * mt7531_ind_mmd_phy_[read,write] to complete this function.
 	 */
-	val = mt7531_ind_c45_phy_read(priv,
+	ret = mt7531_ind_c45_phy_read(priv,
 				      MT753X_CTRL_PHY_ADDR(priv->mdiodev->addr),
 				      MDIO_MMD_VEND2, CORE_PLL_GROUP4);
+	if (ret < 0)
+		return ret;
+
+	val = ret;
 	val |= MT7531_RG_SYSPLL_DMY2 | MT7531_PHY_PLL_BYPASS_MODE;
 	val &= ~MT7531_PHY_PLL_OFF;
-	mt7531_ind_c45_phy_write(priv,
-				 MT753X_CTRL_PHY_ADDR(priv->mdiodev->addr),
-				 MDIO_MMD_VEND2, CORE_PLL_GROUP4, val);
+	ret = mt7531_ind_c45_phy_write(priv,
+				       MT753X_CTRL_PHY_ADDR(priv->mdiodev->addr),
+				       MDIO_MMD_VEND2, CORE_PLL_GROUP4, val);
+	if (ret < 0)
+		return ret;
 
 	/* Disable EEE advertisement on the switch PHYs. */
 	for (i = MT753X_CTRL_PHY_ADDR(priv->mdiodev->addr);
diff --git a/drivers/net/pcs/pcs-mtk-lynxi.c b/drivers/net/pcs/pcs-mtk-lynxi.c
index a753bd88cbc2..7290fc3e5d18 100644
--- a/drivers/net/pcs/pcs-mtk-lynxi.c
+++ b/drivers/net/pcs/pcs-mtk-lynxi.c
@@ -113,8 +113,11 @@ static void mtk_pcs_lynxi_get_state(struct phylink_pcs *pcs,
 	unsigned int bm, adv;
 
 	/* Read the BMSR and LPA */
-	regmap_read(mpcs->regmap, SGMSYS_PCS_CONTROL_1, &bm);
-	regmap_read(mpcs->regmap, SGMSYS_PCS_ADVERTISE, &adv);
+	if (regmap_read(mpcs->regmap, SGMSYS_PCS_CONTROL_1, &bm) ||
+	    regmap_read(mpcs->regmap, SGMSYS_PCS_ADVERTISE, &adv)) {
+		state->link = false;
+		return;
+	}
 
 	phylink_mii_c22_pcs_decode_state(state, neg_mode,
 					 FIELD_GET(SGMII_BMSR, bm),