Re: [PATCH] net: fec: fix enet_out clock handling

[Andrew Lunn]

On Fri, Nov 27, 2015 at 02:39:10PM +0100, Lothar Waßmann 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
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