[PATCH net-next 03/10] net: mdio: C22 is now optional, EOPNOTSUPP if not provided

From: Andrew Lunn <andrew@lunn.ch>
To: netdev <netdev@vger.kernel.org>
Cc: Sean Wang <sean.wang@mediatek.com>,
	Landen Chao <Landen.Chao@mediatek.com>,
	DENG Qingfang <dqfext@gmail.com>, Andrew Lunn <andrew@lunn.ch>,
	Vivien Didelot <vivien.didelot@gmail.com>,
	Florian Fainelli <f.fainelli@gmail.com>,
	Vladimir Oltean <olteanv@gmail.com>,
	Matthias Brugger <matthias.bgg@gmail.com>,
	Joakim Zhang <qiangqing.zhang@nxp.com>,
	Sergey Shtylyov <s.shtylyov@omp.ru>,
	Heiner Kallweit <hkallweit1@gmail.com>,
	Russell King <linux@armlinux.org.uk>,
	Tobias Waldekranz <tobias@waldekranz.com>,
	Marcin Wojtas <mw@semihalf.com>,
	Calvin Johnson <calvin.johnson@oss.nxp.com>,
	Markus Koch <markus@notsyncing.net>,
	Geert Uytterhoeven <geert+renesas@glider.be>,
	Yang Yingliang <yangyingliang@huawei.com>,
	Hao Chen <chenhao288@hisilicon.com>
Subject: [PATCH net-next 03/10] net: mdio: C22 is now optional, EOPNOTSUPP if not provided
Date: Sun,  8 May 2022 17:30:42 +0200	[thread overview]
Message-ID: <20220508153049.427227-4-andrew@lunn.ch> (raw)
In-Reply-To: <20220508153049.427227-1-andrew@lunn.ch>

When performing a C22 operation, check that the bus driver actually
provides the methods, and return -EOPNOTSUPP if not. C45 only busses
do exist, and in future their C22 methods will be NULL.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
---
 drivers/net/phy/mdio_bus.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c
index 818d22fb3cb5..4638ae3e13e3 100644
--- a/drivers/net/phy/mdio_bus.c
+++ b/drivers/net/phy/mdio_bus.c
@@ -767,7 +767,10 @@ int __mdiobus_read(struct mii_bus *bus, int addr, u32 regnum)
 
 	lockdep_assert_held_once(&bus->mdio_lock);
 
-	retval = bus->read(bus, addr, regnum);
+	if (bus->read)
+		retval = bus->read(bus, addr, regnum);
+	else
+		retval = -EOPNOTSUPP;
 
 	trace_mdio_access(bus, 1, addr, regnum, retval, retval);
 	mdiobus_stats_acct(&bus->stats[addr], true, retval);
@@ -793,7 +796,10 @@ int __mdiobus_write(struct mii_bus *bus, int addr, u32 regnum, u16 val)
 
 	lockdep_assert_held_once(&bus->mdio_lock);
 
-	err = bus->write(bus, addr, regnum, val);
+	if (bus->write)
+		err = bus->write(bus, addr, regnum, val);
+	else
+		err = -EOPNOTSUPP;
 
 	trace_mdio_access(bus, 0, addr, regnum, val, err);
 	mdiobus_stats_acct(&bus->stats[addr], false, err);
-- 
2.36.0

