net: dsa: felix: Don't restart PCS SGMII AN if not needed

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Some PHYs like VSC8234 don't like it when AN restarts on their system side
and they restart line side AN too, going into an endless link up/down loop.
Don't restart PCS AN if link is up already.

Although in theory this feedback loop should be possible with the other
in-band AN modes too, for some reason it was not seen with the VSC8514
QSGMII and AQR412 USXGMII PHYs. So keep this logic only for SGMII where
the problem was found.

Fixes: bdeced75b1 ("net: dsa: felix: Add PCS operations for PHYLINK")
Suggested-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: Alex Marginean <alexandru.marginean@nxp.com>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

...

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Alex Marginean 2020-01-16 20:09:59 +02:00 • committed by David S. Miller

parent 062a33b1ad

commit 8c6123e150

1 changed files with 21 additions and 0 deletions

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drivers/net/dsa/ocelot/felix_vsc9959.c

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