net: stmmac: avoid PHY speed change when configuring MTU

There is no need to do the speed-down, speed-up dance when changing
the MTU as there is little power saving that can be gained from such
a brief interval between these, and the autonegotiation they cause
takes much longer.

Move the calls to phylink_speed_up() and phylink_speed_down() into
stmmac_open() and stmmac_release() respectively, reducing the work
done in the __-variants of these functions.

Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Reviewed-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Reviewed-by: Gatien Chevallier <gatien.chevallier@foss.st.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://patch.msgid.link/E1v945T-0000000AmeV-2BvU@rmk-PC.armlinux.org.uk
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 3728afa701c6ee936a3431d365833d9be8c05859..500cfd19e6b5f93f76387d906076df36273d3229 100644 (file)
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -3963,8 +3963,6 @@ static int __stmmac_open(struct net_device *dev,
        stmmac_init_coalesce(priv);
 
        phylink_start(priv->phylink);
-       /* We may have called phylink_speed_down before */
-       phylink_speed_up(priv->phylink);
 
        ret = stmmac_request_irq(dev);
        if (ret)
@@ -4015,6 +4013,9 @@ static int stmmac_open(struct net_device *dev)
 
        kfree(dma_conf);
 
+       /* We may have called phylink_speed_down before */
+       phylink_speed_up(priv->phylink);
+
        return ret;
 
 err_disconnect_phy:
@@ -4032,13 +4033,6 @@ static void __stmmac_release(struct net_device *dev)
        struct stmmac_priv *priv = netdev_priv(dev);
        u32 chan;
 
-       /* If the PHY or MAC has WoL enabled, then the PHY will not be
-        * suspended when phylink_stop() is called below. Set the PHY
-        * to its slowest speed to save power.
-        */
-       if (device_may_wakeup(priv->device))
-               phylink_speed_down(priv->phylink, false);
-
        /* Stop and disconnect the PHY */
        phylink_stop(priv->phylink);
 
@@ -4078,6 +4072,13 @@ static int stmmac_release(struct net_device *dev)
 {
        struct stmmac_priv *priv = netdev_priv(dev);
 
+       /* If the PHY or MAC has WoL enabled, then the PHY will not be
+        * suspended when phylink_stop() is called below. Set the PHY
+        * to its slowest speed to save power.
+        */
+       if (device_may_wakeup(priv->device))
+               phylink_speed_down(priv->phylink, false);
+
        __stmmac_release(dev);
 
        phylink_disconnect_phy(priv->phylink);