This is a note to let you know that I've just added the patch titled net: dsa: sja1105: disallow C45 transactions on the BASE-TX MDIO bus to the 6.0-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: net-dsa-sja1105-disallow-c45-transactions-on-the-bas.patch and it can be found in the queue-6.0 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 0158b4b7b23ff257e9687497fff9a10567cc0118 Author: Vladimir Oltean <vladimir.oltean@xxxxxxx> Date: Wed Nov 16 12:06:53 2022 +0200 net: dsa: sja1105: disallow C45 transactions on the BASE-TX MDIO bus [ Upstream commit 24deec6b9e4a051635f75777844ffc184644fec9 ] You'd think people know that the internal 100BASE-TX PHY on the SJA1110 responds only to clause 22 MDIO transactions, but they don't :) When a clause 45 transaction is attempted, sja1105_base_tx_mdio_read() and sja1105_base_tx_mdio_write() don't expect "reg" to contain bit 30 set (MII_ADDR_C45) and pack this value into the SPI transaction buffer. But the field in the SPI buffer has a width smaller than 30 bits, so we see this confusing message from the packing() API rather than a proper rejection of C45 transactions: Call trace: dump_stack+0x1c/0x38 sja1105_pack+0xbc/0xc0 [sja1105] sja1105_xfer+0x114/0x2b0 [sja1105] sja1105_xfer_u32+0x44/0xf4 [sja1105] sja1105_base_tx_mdio_read+0x44/0x7c [sja1105] mdiobus_read+0x44/0x80 get_phy_c45_ids+0x70/0x234 get_phy_device+0x68/0x15c fwnode_mdiobus_register_phy+0x74/0x240 of_mdiobus_register+0x13c/0x380 sja1105_mdiobus_register+0x368/0x490 [sja1105] sja1105_setup+0x94/0x119c [sja1105] Cannot store 401d2405 inside bits 24-4 (would truncate) Fixes: 5a8f09748ee7 ("net: dsa: sja1105: register the MDIO buses for 100base-T1 and 100base-TX") Signed-off-by: Vladimir Oltean <vladimir.oltean@xxxxxxx> Reviewed-by: Andrew Lunn <andrew@xxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/net/dsa/sja1105/sja1105_mdio.c b/drivers/net/dsa/sja1105/sja1105_mdio.c index 215dd17ca790..4059fcc8c832 100644 --- a/drivers/net/dsa/sja1105/sja1105_mdio.c +++ b/drivers/net/dsa/sja1105/sja1105_mdio.c @@ -256,6 +256,9 @@ static int sja1105_base_tx_mdio_read(struct mii_bus *bus, int phy, int reg) u32 tmp; int rc; + if (reg & MII_ADDR_C45) + return -EOPNOTSUPP; + rc = sja1105_xfer_u32(priv, SPI_READ, regs->mdio_100base_tx + reg, &tmp, NULL); if (rc < 0) @@ -272,6 +275,9 @@ static int sja1105_base_tx_mdio_write(struct mii_bus *bus, int phy, int reg, const struct sja1105_regs *regs = priv->info->regs; u32 tmp = val; + if (reg & MII_ADDR_C45) + return -EOPNOTSUPP; + return sja1105_xfer_u32(priv, SPI_WRITE, regs->mdio_100base_tx + reg, &tmp, NULL); }