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From:   DENG Qingfang <dqfext@gmail.com>
To:     Russell King - ARM Linux admin <linux@armlinux.org.uk>
Cc:     =?iso-8859-1?Q?Ren=E9?= van Dorst <opensource@vdorst.com>,
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        netdev@vger.kernel.org, Weijie Gao <weijie.gao@mediatek.com>,
        Chuanhong Guo <gch981213@gmail.com>,
        Frank Wunderlich <frank-w@public-files.de>,
        Thomas Gleixner <tglx@linutronix.de>,
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Subject: Re: [RFC v4 net-next 1/4] net: phy: add MediaTek PHY driver
Date:   Thu, 15 Apr 2021 17:49:02 +0800
Message-Id: <20210415094902.2946-1-dqfext@gmail.com>
In-Reply-To: <20210413131259.GP1463@shell.armlinux.org.uk>
References: <20210412034237.2473017-1-dqfext@gmail.com> <20210412034237.2473017-2-dqfext@gmail.com> <20210412070449.Horde.wg9CWXW8V9o0P-heKYtQpVh@www.vdorst.com> <20210412150836.929610-1-dqfext@gmail.com> <20210413035920.1422364-1-dqfext@gmail.com> <20210413131259.GP1463@shell.armlinux.org.uk>
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On Tue, Apr 13, 2021 at 02:12:59PM +0100, Russell King - ARM Linux admin wrote:
> On Tue, Apr 13, 2021 at 11:59:20AM +0800, DENG Qingfang wrote:
> > Within 12 hours, I got some spontaneous link down/ups when EEE is enabled:
> > 
> > [16334.236233] mt7530 mdio-bus:1f wan: Link is Down
> > [16334.241340] br-lan: port 3(wan) entered disabled state
> > [16337.355988] mt7530 mdio-bus:1f wan: Link is Up - 1Gbps/Full - flow control rx/tx
> > [16337.363468] br-lan: port 3(wan) entered blocking state
> > [16337.368638] br-lan: port 3(wan) entered forwarding state
> > 
> > The cable is a 30m Cat.6 and never has such issue when EEE is disabled.
> > Perhaps WAKEUP_TIME_1000/100 or some PHY registers need to be fine-tuned,
> > but for now I think it should be disabled by default.
> 
> Experience with Atheros AR8035 which has a very similar issue would
> suggest that before resorting to the blunt hammer of disabling
> SmartEEE, one should definitely experiment with the 1G Tw settings.
> 
> Using 24us for 1G speeds on AR8035 helps a great deal, whereas the PHY
> defaults to 17us for 1G and 23us for 100M.

I set the 1G Tw to maximum 255us and still got the link issue..