Date: Mon, 30 Nov 2015 03:07:31 +0100
From: Andrew Lunn <andrew@lunn.ch>
To: Lothar =?iso-8859-1?Q?Wa=DFmann?= <LW@KARO-electronics.de>
Cc: "David S. Miller" <davem@davemloft.net>,
        Fabio Estevam <fabio.estevam@freescale.com>,
        Kevin Hao <haokexin@gmail.com>, Lucas Stach <l.stach@pengutronix.de>,
        Nimrod Andy <B38611@freescale.com>,
        Philippe Reynes <tremyfr@gmail.com>,
        Russell King <rmk+kernel@arm.linux.org.uk>,
        Uwe =?iso-8859-1?Q?Kleine-K=F6nig?= 
	<u.kleine-koenig@pengutronix.de>,
        linux-kernel@vger.kernel.org, netdev@vger.kernel.org,
        Stefan Agner <stefan@agner.ch>
Subject: Re: [PATCH] net: fec: fix enet_out clock handling
Message-ID: <20151130020731.GB32662@lunn.ch>
References: <1448631550-943-1-git-send-email-LW@KARO-electronics.de>
MIME-Version: 1.0
Content-Type: text/plain; charset=iso-8859-1
Content-Disposition: inline
Content-Transfer-Encoding: 8bit
In-Reply-To: <1448631550-943-1-git-send-email-LW@KARO-electronics.de>
User-Agent: Mutt/1.5.21 (2010-09-15)
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 1120
Lines: 27

On Fri, Nov 27, 2015 at 02:39:10PM +0100, Lothar Wa?mann wrote:
> When ENET_OUT is being used as reference clock for an external PHY,
> the clock must not be disabled while the PHY is active. Otherwise the
> PHY may lose its internal state and require a reset to become
> functional again.
> 
> A symptom for this bug is a network interface that constantly toggles
> between UP and DOWN state:
> fec 800f0000.ethernet eth0: Link is Up - 100Mbps/Full - flow control rx/tx
> fec 800f0000.ethernet eth0: Link is Down
> fec 800f0000.ethernet eth0: Link is Up - 100Mbps/Full - flow control rx/tx
> fec 800f0000.ethernet eth0: Link is Down

Hi Lothar

When does this up/down happen? During normal operation when the link
is administrative up?

When did this start happening? Did it happen before 
8fff755e9f8d net: fec: Ensure clocks are enabled while using mdio bus

	     Andrew
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/