netdev - [PATCH net-next] net: phy: don't double-read link status register if link is up

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Message-ID: <fd5559ed-6843-9ce5-fbb2-d9ffa9eb92e9@gmail.com>
Date:   Thu, 7 Feb 2019 20:22:20 +0100
From:   Heiner Kallweit <hkallweit1@...il.com>
To:     Andrew Lunn <andrew@...n.ch>,
        Florian Fainelli <f.fainelli@...il.com>,
        David Miller <davem@...emloft.net>
Cc:     "netdev@...r.kernel.org" <netdev@...r.kernel.org>
Subject: [PATCH net-next] net: phy: don't double-read link status register if
 link is up

The link status register latches link-down events. Therefore, if link
is reported as being up, there's no need for a second read.

Signed-off-by: Heiner Kallweit <hkallweit1@...il.com>
---
 drivers/net/phy/phy-c45.c    | 2 ++
 drivers/net/phy/phy_device.c | 6 +++++-
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/net/phy/phy-c45.c b/drivers/net/phy/phy-c45.c
index d429c6a3e..19334fe5f 100644
--- a/drivers/net/phy/phy-c45.c
+++ b/drivers/net/phy/phy-c45.c
@@ -147,6 +147,8 @@ int genphy_c45_read_link(struct phy_device *phydev)
 			val = phy_read_mmd(phydev, devad, MDIO_STAT1);
 			if (val < 0)
 				return val;
+			else if (val & MDIO_STAT1_LSTATUS)
+				continue;
 		}
 
 		val = phy_read_mmd(phydev, devad, MDIO_STAT1);
diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
index d490cd2a8..9369e1323 100644
--- a/drivers/net/phy/phy_device.c
+++ b/drivers/net/phy/phy_device.c
@@ -1735,8 +1735,12 @@ int genphy_update_link(struct phy_device *phydev)
 	 */
 	if (!phy_polling_mode(phydev)) {
 		status = phy_read(phydev, MII_BMSR);
-		if (status < 0)
+		if (status < 0) {
 			return status;
+		} else if (status & BMSR_LSTATUS) {
+			phydev->link = 1;
+			return 0;
+		}
 	}
 
 	/* Read link and autonegotiation status */
-- 
2.20.1