netdev - [PATCH net-next] net: stmmac: mdio: clean up c22/c45 accessor split

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Message-Id: <E1urGBn-00000000DCH-3swS@rmk-PC.armlinux.org.uk>
Date: Wed, 27 Aug 2025 14:27:47 +0100
From: "Russell King (Oracle)" <rmk+kernel@...linux.org.uk>
To: Andrew Lunn <andrew@...n.ch>,
	Heiner Kallweit <hkallweit1@...il.com>
Cc: Alexandre Torgue <alexandre.torgue@...s.st.com>,
	Andrew Lunn <andrew+netdev@...n.ch>,
	"David S. Miller" <davem@...emloft.net>,
	Eric Dumazet <edumazet@...gle.com>,
	Jakub Kicinski <kuba@...nel.org>,
	linux-arm-kernel@...ts.infradead.org,
	linux-stm32@...md-mailman.stormreply.com,
	Maxime Coquelin <mcoquelin.stm32@...il.com>,
	netdev@...r.kernel.org,
	Paolo Abeni <pabeni@...hat.com>
Subject: [PATCH net-next] net: stmmac: mdio: clean up c22/c45 accessor split

The C45 accessors were setting the GR (register number) field twice,
once with the 16-bit register address truncated to five bits, and
then overwritten with the C45 devad. This is harmless since the field
was being cleared prior to being updated with the C45 devad, except
for the extra work.

Remove the redundant code.

Signed-off-by: Russell King (Oracle) <rmk+kernel@...linux.org.uk>
---
Untested, as I don't have my Jetson Xavier NX platform with me (and
probably won't do for a few weeks.)

While this patch has been prepared on top of "net: stmmac: mdio: use
netdev_priv() directly" it shouldn't conflict if that patch is not
applied before this one.

 drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c
index 86021e6b67b2..da4542be756a 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c
@@ -311,12 +311,10 @@ static int stmmac_mdio_read_c45(struct mii_bus *bus, int phyaddr, int devad,
 
 	value |= (phyaddr << priv->hw->mii.addr_shift)
 		& priv->hw->mii.addr_mask;
-	value |= (phyreg << priv->hw->mii.reg_shift) & priv->hw->mii.reg_mask;
 	value |= (priv->clk_csr << priv->hw->mii.clk_csr_shift)
 		& priv->hw->mii.clk_csr_mask;
 	value |= MII_GMAC4_READ;
 	value |= MII_GMAC4_C45E;
-	value &= ~priv->hw->mii.reg_mask;
 	value |= (devad << priv->hw->mii.reg_shift) & priv->hw->mii.reg_mask;
 
 	data |= phyreg << MII_GMAC4_REG_ADDR_SHIFT;
@@ -409,14 +407,12 @@ static int stmmac_mdio_write_c45(struct mii_bus *bus, int phyaddr,
 
 	value |= (phyaddr << priv->hw->mii.addr_shift)
 		& priv->hw->mii.addr_mask;
-	value |= (phyreg << priv->hw->mii.reg_shift) & priv->hw->mii.reg_mask;
 
 	value |= (priv->clk_csr << priv->hw->mii.clk_csr_shift)
 		& priv->hw->mii.clk_csr_mask;
 
 	value |= MII_GMAC4_WRITE;
 	value |= MII_GMAC4_C45E;
-	value &= ~priv->hw->mii.reg_mask;
 	value |= (devad << priv->hw->mii.reg_shift) & priv->hw->mii.reg_mask;
 
 	data |= phyreg << MII_GMAC4_REG_ADDR_SHIFT;
-- 
2.47.2