Commit 9f239fe6 authored Jan 12, 2018 by Andrew Lunn Committed by David S. Miller Jan 15, 2018

net: phy: Have __phy_modify return 0 on success



__phy_modify would return the old value of the register before it was
modified. Thus on success, it does not return 0, but a positive value.
Thus functions using phy_modify, which is a wrapper around
__phy_modify, can start returning > 0 on success, rather than 0. As a
result, breakage has been noticed in various places, where 0 was
assumed.

Code inspection does not find any current location where the return of
the old value is currently used. So have __phy_modify return 0 on
success. When there is a real need for the old value, either a new
accessor can be added, or an additional parameter passed.

Fixes: fea23fb5 ("net: phy: convert read-modify-write to phy_modify()")
Fixes: 2b74e5be ("net: phy: add phy_modify() accessor")
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Tested-by: Niklas Cassel <niklas.cassel@axis.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 564737f9

drivers/net/phy/phy-core.c

+6 −7

Original line number	Diff line number	Diff line
		@@ -336,16 +336,15 @@ EXPORT_SYMBOL(phy_write_mmd);
		*/
		int __phy_modify(struct phy_device *phydev, u32 regnum, u16 mask, u16 set)
		{
		int ret, res;
		int ret;

		ret = __phy_read(phydev, regnum);
		if (ret >= 0) {
		res = __phy_write(phydev, regnum, (ret & ~mask) \| set);
		if (res < 0)
		ret = res;
		}

		if (ret < 0)
		return ret;

		ret = __phy_write(phydev, regnum, (ret & ~mask) \| set);

		return ret < 0 ? ret : 0;
		}
		EXPORT_SYMBOL_GPL(__phy_modify);