linux-kernel - Re: [PATCH 2/2] net: phy: Provide Module 4 KSZ9477 errata (DS80000754C)

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20230830123749.1486c4b7@wsk>
Date:   Wed, 30 Aug 2023 12:37:49 +0200
From:   Lukasz Majewski <lukma@...x.de>
To:     Michal Swiatkowski <michal.swiatkowski@...ux.intel.com>
Cc:     Eric Dumazet <edumazet@...gle.com>, Andrew Lunn <andrew@...n.ch>,
        davem@...emloft.net, Woojung Huh <woojung.huh@...rochip.com>,
        Vladimir Oltean <olteanv@...il.com>,
        Oleksij Rempel <o.rempel@...gutronix.de>,
        Tristram.Ha@...rochip.com, Florian Fainelli <f.fainelli@...il.com>,
        Jakub Kicinski <kuba@...nel.org>,
        Paolo Abeni <pabeni@...hat.com>, UNGLinuxDriver@...rochip.com,
        Russell King <linux@...linux.org.uk>,
        Heiner Kallweit <hkallweit1@...il.com>, netdev@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH 2/2] net: phy: Provide Module 4 KSZ9477 errata
 (DS80000754C)

Hi Michal,

> On Wed, Aug 30, 2023 at 11:21:19AM +0200, Lukasz Majewski wrote:
> > The KSZ9477 errata points out (in 'Module 4') the link up/down
> > problem when EEE (Energy Efficient Ethernet) is enabled in the
> > device to which the KSZ9477 tries to auto negotiate.
> > 
> > The suggested workaround is to clear advertisement of EEE for PHYs
> > in this chip driver.
> > 
> > Signed-off-by: Lukasz Majewski <lukma@...x.de>  
> Hi,
> 
> As the net is target you should add fixes tag which the commit that
> your changes is fixing (workarounding :) )
> 

I'm applying code for vendor's errata.

I will search when it has been modified.

> > ---
> >  drivers/net/phy/micrel.c | 31 ++++++++++++++++++++++++++++++-
> >  1 file changed, 30 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/net/phy/micrel.c b/drivers/net/phy/micrel.c
> > index 87b090ad2874..469dcd8a5711 100644
> > --- a/drivers/net/phy/micrel.c
> > +++ b/drivers/net/phy/micrel.c
> > @@ -1418,6 +1418,35 @@ static int ksz9131_get_features(struct
> > phy_device *phydev) return 0;
> >  }
> >  
> > +static int ksz9477_get_features(struct phy_device *phydev)
> > +{
> > +	__ETHTOOL_DECLARE_LINK_MODE_MASK(zero) = { 0, };  
> = { 0 };

Ok.

> 
> > +	int ret;
> > +
> > +	ret = genphy_read_abilities(phydev);
> > +	if (ret)
> > +		return ret;
> > +
> > +	/* KSZ9477 Errata DS80000754C
> > +	 *
> > +	 * Module 4: Energy Efficient Ethernet (EEE) feature
> > select must be
> > +	 * manually disabled
> > +	 *   The EEE feature is enabled by default, but it is not
> > fully
> > +	 *   operational. It must be manually disabled through
> > register
> > +	 *   controls. If not disabled, the PHY ports can
> > auto-negotiate
> > +	 *   to enable EEE, and this feature can cause link drops
> > when linked
> > +	 *   to another device supporting EEE.
> > +	 *
> > +	 *   Although, the KSZ9477 MMD register
> > +	 *   (MMD_DEVICE_ID_EEE_ADV.MMD_EEE_ADV) advertise that
> > EEE is
> > +	 *   operational one needs to manualy clear them to follow
> > the chip
> > +	 *   errata.
> > +	 */
> > +	linkmode_and(phydev->supported_eee, phydev->supported,
> > zero); +
> > +	return 0;
> > +}
> > +
> >  #define KSZ8873MLL_GLOBAL_CONTROL_4	0x06
> >  #define KSZ8873MLL_GLOBAL_CONTROL_4_DUPLEX	BIT(6)
> >  #define KSZ8873MLL_GLOBAL_CONTROL_4_SPEED	BIT(4)
> > @@ -4871,7 +4900,7 @@ static struct phy_driver ksphy_driver[] = {
> >  	.handle_interrupt = kszphy_handle_interrupt,
> >  	.suspend	= genphy_suspend,
> >  	.resume		= genphy_resume,
> > -	.get_features	= ksz9131_get_features,
> > +	.get_features	= ksz9477_get_features,
> >  } };
> >  
> >  module_phy_driver(ksphy_driver);
> > -- 
> > 2.20.1
> >   




Best regards,

Lukasz Majewski

--

DENX Software Engineering GmbH,      Managing Director: Erika Unter
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-59 Fax: (+49)-8142-66989-80 Email: lukma@...x.de

Content of type "application/pgp-signature" skipped