Message-ID: <1524164724.17017.35.camel@nxp.com>
Subject: Re: [PATCH 4.9 181/310] net: phy: micrel: Restore led_mode and
 clk_sel on resume
From: Leonard Crestez <leonard.crestez@nxp.com>
To: Florian Fainelli <f.fainelli@gmail.com>,
        Andrew Lunn <andrew@lunn.ch>
Cc: Grygorii Strashko <grygorii.strashko@ti.com>,
        open list <linux-kernel@vger.kernel.org>,
        linux- stable <stable@vger.kernel.org>,
        "David S. Miller" <davem@davemloft.net>,
        Sasha Levin <alexander.levin@microsoft.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Naresh Kamboju <naresh.kamboju@linaro.org>,
        chris.ruehl@gtsys.com.hk, Lars Persson <lars.persson@axis.com>
Date: Thu, 19 Apr 2018 22:05:24 +0300
In-Reply-To: <223ffd4d-567e-6c5c-9581-5304494dd0b3@gmail.com>
References: <20180411183622.305902791@linuxfoundation.org>
         <20180411183630.390575424@linuxfoundation.org>
         <CA+G9fYtR_3AXKvhrkE3WEZhVOX6XwJ1r38PLav1XKkz4L4eQZQ@mail.gmail.com>
         <1524154267.17017.15.camel@nxp.com>
         <CA+G9fYs00cOVxuWYkfUxkdYZX5NGeTgBpwimCJ7tJbANbZwGEA@mail.gmail.com>
         <223ffd4d-567e-6c5c-9581-5304494dd0b3@gmail.com>
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On Thu, 2018-04-19 at 11:32 -0700, Florian Fainelli wrote:
> +Others who reported the same problem
> On 04/19/2018 11:24 AM, Naresh Kamboju wrote:
> > On 19 April 2018 at 21:41, Leonard Crestez <leonard.crestez@nxp.com> wrote:
> > > 
> > > Looking at this dump I'm guessing that phydev->priv is NULL at the
> > > start of kszphy_config_reset and this really shouldn't be happening.
> > > 
> > > The phydev->priv field is initialized by kszphy_probe but your
> > > particular phy (KSZ9031) in linux-4.9.y does not seem to have .probe =
> > > kszphy_probe assigned in the struct phy_driver ksphy_driver array.
> > > 
> > > In upstream this was added by commit bfe72442578b ("net: phy: micrel:
> > > fix crash when statistic requested for KSZ9031 phy"). The message for
> > > that patch claims to fix a kernel crash on this command:
> > > 
> > >     ethtool --phy-statistics eth0
> > > 
> > > Looking at the code this issue should affect linux-4.9.y on your board.
> > > Naresh: can you please check?
> > After reverting the patch i have run this command and kernel oops
> > showed up.
> > ethtool --phy-statistics eth0
> > 
> > PC is at kszphy_get_stats+0x74/0xa8
> > 
> > ethtool --phy-statistics eth0 crashed on x15
> > 
> Chris proposed the following patch, which has not been formally
> submitted yet:
> 
> Meanwhile, Greg seems to have reverted the offending patch, so we should
> be good with 4.9.95.

I don't object to reverting my patch from linux-4.14.y but it seems all
the affected hardware would also be affected by the crash from ethtool
--phy-statistics eth0. Adding bfe72442578b to stable would be great
because it fixes more than the patch in the title.

In the other thread there is a mention that "Micrel KSZ8795",
"Micrel KSZ886X Switch", "Micrel KSZ8061", and "Micrel KS8737" might
still have problems after bfe72442578b. Is this because they have
kszphy_config_init but not kszphy_probe? All versions of
kszphy_config_init seem to check for a NULL priv.

--
Regards,
Leonard