netdev - Issue with commit fea23fb591cc "net: phy: convert read-modify-write to phy

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Message-ID: <8cf4bdaa-bd05-1962-f1d0-6cb84db31588@googlemail.com>
Date:   Thu, 4 Jan 2018 08:00:53 +0100
From:   Heiner Kallweit <hkallweit1@...il.com>
To:     Russell King <rmk+kernel@...linux.org.uk>,
        Andrew Lunn <andrew@...n.ch>,
        "David S. Miller" <davem@...emloft.net>
Cc:     "netdev@...r.kernel.org" <netdev@...r.kernel.org>
Subject: Issue with commit fea23fb591cc "net: phy: convert read-modify-write
 to phy_modify()"

Parameter mask of phy_modify() holds the bits to be cleared.
In the mentioned commit parameter mask seems to be inverted in
few cases, what IMO is wrong (see example).
Maybe I miss something, could you please check?

And somehow related:
When adding such helpers, wouldn't it make sense to add
helpers for setting / clearing bits too? Something like:
phy_set_bits(phydev, reg, val) -> phy_modify(phydev, reg, 0, val)

Rgds, Heiner

 int genphy_resume(struct phy_device *phydev)
 {
-	int value;
-
-	value = phy_read(phydev, MII_BMCR);
-	phy_write(phydev, MII_BMCR, value & ~BMCR_PDOWN);
-
-	return 0;
+	return phy_modify(phydev, MII_BMCR, ~BMCR_PDOWN, 0);
 }