linux-kernel - [PATCH] gianfar: Reduce logging noise seen due to phy polling if link is down

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Date:	Mon,  2 Mar 2015 12:03:27 -0800
From:	Guenter Roeck <linux@...ck-us.net>
To:	netdev@...r.kernel.org
Cc:	"David S. Miller" <davem@...emloft.net>,
	Guenter Roeck <linux@...ck-us.net>,
	Claudiu Manoil <claudiu.manoil@...escale.com>,
	linux-kernel@...r.kernel.org
Subject: [PATCH] gianfar: Reduce logging noise seen due to phy polling if link is down

Commit 6ce29b0e2a04 ("gianfar: Avoid unnecessary reg accesses in adjust_link()")
eliminates unnecessary calls to adjust_link for phy devices which don't support
interrupts and need polling. As part of that work, the 'new_state' local flag,
which was used to reduce logging noise on the console, was eliminated.

Unfortunately, that means that a 'Link is Down' log message will now be
issued continuously if a link is configured as UP, the link state is down,
and the associated phy requires polling. This occurs because priv->oldduplex
is -1 in this case, which always differs from phydev->duplex. In addition,
phydev->speed may also differ from priv->oldspeed.  gfar_update_link_state()
is therefore called each time a phy is polled, even if the link state did not
change.

Cc: Claudiu Manoil <claudiu.manoil@...escale.com>
Signed-off-by: Guenter Roeck <linux@...ck-us.net>
---
 drivers/net/ethernet/freescale/gianfar.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/freescale/gianfar.c b/drivers/net/ethernet/freescale/gianfar.c
index 43df788..178e540 100644
--- a/drivers/net/ethernet/freescale/gianfar.c
+++ b/drivers/net/ethernet/freescale/gianfar.c
@@ -3162,8 +3162,8 @@ static void adjust_link(struct net_device *dev)
 	struct phy_device *phydev = priv->phydev;

 	if (unlikely(phydev->link != priv->oldlink ||
-		     phydev->duplex != priv->oldduplex ||
-		     phydev->speed != priv->oldspeed))
+		     (phydev->link && (phydev->duplex != priv->oldduplex ||
+				       phydev->speed != priv->oldspeed))))
 		gfar_update_link_state(priv);
 }

-- 
2.1.0

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