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Date:   Wed, 30 Nov 2022 18:10:42 +0100
From:   Andrew Lunn <andrew@lunn.ch>
To:     "Russell King (Oracle)" <linux@armlinux.org.uk>
Cc:     Frank <Frank.Sae@motor-comm.com>, Peter Geis <pgwipeout@gmail.com>,
        Heiner Kallweit <hkallweit1@gmail.com>,
        "David S . Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>, yinghong.zhang@motor-comm.com,
        fei.zhang@motor-comm.com, hua.sun@motor-comm.com,
        netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH net-next] net: phy: Add driver for Motorcomm yt8531
 gigabit ethernet phy
Message-ID: <Y4eOkiaRywaUJa9n@lunn.ch>
References: <20221130094928.14557-1-Frank.Sae@motor-comm.com>
 <Y4copjAzKpGSeunB@shell.armlinux.org.uk>
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On Wed, Nov 30, 2022 at 09:55:50AM +0000, Russell King (Oracle) wrote:
> On Wed, Nov 30, 2022 at 05:49:28PM +0800, Frank wrote:
> > +/**
> > + * yt8531_set_wol() - turn wake-on-lan on or off
> > + * @phydev: a pointer to a &struct phy_device
> > + * @wol: a pointer to a &struct ethtool_wolinfo
> > + *
> > + * NOTE: YTPHY_WOL_CONFIG_REG, YTPHY_WOL_MACADDR2_REG, YTPHY_WOL_MACADDR1_REG
> > + * and YTPHY_WOL_MACADDR0_REG are common ext reg.
> > + *
> > + * returns 0 or negative errno code
> > + */
> > +static int yt8531_set_wol(struct phy_device *phydev,
> > +			  struct ethtool_wolinfo *wol)
> > +{
> 
> So this is called from the .set_wol method directly, and won't have the
> MDIO bus lock taken...

Hi Frank

This is not the first time Russell has pointed out your locking is
wrong.

How about adding a check in functions which should be called with the
lock taken really do have the lock taken?

ASSERT_RTNL() but for an MDIO bus.

	Andrew