netdev - [PATCH] net: phy: at803x: stop switching phy delay config needlessly

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Date:   Fri,  9 Aug 2019 01:57:54 +0100
From:   André Draszik <git@...red.net>
To:     linux-kernel@...r.kernel.org
Cc:     André Draszik <git@...red.net>,
        Andrew Lunn <andrew@...n.ch>,
        Florian Fainelli <f.fainelli@...il.com>,
        Heiner Kallweit <hkallweit1@...il.com>,
        "David S. Miller" <davem@...emloft.net>, netdev@...r.kernel.org
Subject: [PATCH] net: phy: at803x: stop switching phy delay config needlessly

This driver does a funny dance disabling and re-enabling
RX and/or TX delays. In any of the RGMII-ID modes, it first
disables the delays, just to re-enable them again right
away. This looks like a needless exercise.

Just enable the respective delays when in any of the
relevant 'id' modes, and disable them otherwise.

Also, remove comments which don't add anything that can't be
seen by looking at the code.

Signed-off-by: André Draszik <git@...red.net>
CC: Andrew Lunn <andrew@...n.ch>
CC: Florian Fainelli <f.fainelli@...il.com>
CC: Heiner Kallweit <hkallweit1@...il.com>
CC: "David S. Miller" <davem@...emloft.net>
CC: netdev@...r.kernel.org
---
 drivers/net/phy/at803x.c | 26 ++++++--------------------
 1 file changed, 6 insertions(+), 20 deletions(-)

diff --git a/drivers/net/phy/at803x.c b/drivers/net/phy/at803x.c
index 222ccd9ecfce..2ab51f552e92 100644
--- a/drivers/net/phy/at803x.c
+++ b/drivers/net/phy/at803x.c
@@ -257,35 +257,21 @@ static int at803x_config_init(struct phy_device *phydev)
 	 *   after HW reset: RX delay enabled and TX delay disabled
 	 *   after SW reset: RX delay enabled, while TX delay retains the
 	 *   value before reset.
-	 *
-	 * So let's first disable the RX and TX delays in PHY and enable
-	 * them based on the mode selected (this also takes care of RGMII
-	 * mode where we expect delays to be disabled)
 	 */
-
-	ret = at803x_disable_rx_delay(phydev);
-	if (ret < 0)
-		return ret;
-	ret = at803x_disable_tx_delay(phydev);
-	if (ret < 0)
-		return ret;
-
 	if (phydev->interface == PHY_INTERFACE_MODE_RGMII_ID ||
 	    phydev->interface == PHY_INTERFACE_MODE_RGMII_RXID) {
-		/* If RGMII_ID or RGMII_RXID are specified enable RX delay,
-		 * otherwise keep it disabled
-		 */
 		ret = at803x_enable_rx_delay(phydev);
-		if (ret < 0)
-			return ret;
+	} else {
+		ret = at803x_disable_rx_delay(phydev);
 	}
+	if (ret < 0)
+		return ret;
 
 	if (phydev->interface == PHY_INTERFACE_MODE_RGMII_ID ||
 	    phydev->interface == PHY_INTERFACE_MODE_RGMII_TXID) {
-		/* If RGMII_ID or RGMII_TXID are specified enable TX delay,
-		 * otherwise keep it disabled
-		 */
 		ret = at803x_enable_tx_delay(phydev);
+	} else {
+		ret = at803x_disable_tx_delay(phydev);
 	}
 
 	return ret;
-- 
2.20.1