[PATCH] net: mvpp2: let phylink manage the carrier state

[Antoine Tenart]

Net drivers using phylink shouldn't mess with the link carrier
themselves and should let phylink manage it. The mvpp2 driver wasn't
following this best practice as the mac_config() function made calls to
change the link carrier state. This led to wrongly reported carrier link
state which, according to Russell, increased a lot the Debian Jessie
boot time as systemd tried to bring up all those interfaces.

This patch fixes this behaviour.

As parts of the driver relied on this misbehaviour from the mac_config()
function, they were fixed as well to call the link_up() function. Also,
the fixed-link configuration relied on the mac_config() function to mess
with the link carrier state. As it does not anymore, if this mode is
used the link_up() function is called explicitly.

Fixes: 4bb043262878 ("net: mvpp2: phylink support")
Reported-by: linux@xxxxxxxxxxxxxxx
Signed-off-by: Antoine Tenart <antoine.tenart@xxxxxxxxxxx>
---
 drivers/net/ethernet/marvell/mvpp2/mvpp2.h    |  1 +
 .../net/ethernet/marvell/mvpp2/mvpp2_main.c   | 27 +++++++++----------
 2 files changed, 13 insertions(+), 15 deletions(-)

diff --git a/drivers/net/ethernet/marvell/mvpp2/mvpp2.h b/drivers/net/ethernet/marvell/mvpp2/mvpp2.h
index 67b9e81b7c02..c8d2bc23d21d 100644
--- a/drivers/net/ethernet/marvell/mvpp2/mvpp2.h
+++ b/drivers/net/ethernet/marvell/mvpp2/mvpp2.h
@@ -613,6 +613,7 @@
 
 /* Port flags */
 #define MVPP2_F_LOOPBACK		BIT(0)
+#define MVPP2_F_FIXED_LINK		BIT(1)
 
 /* Marvell tag types */
 enum mvpp2_tag_type {
diff --git a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
index 28500417843e..19d48992f213 100644
--- a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
+++ b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
@@ -58,6 +58,8 @@ static struct {
  */
 static void mvpp2_mac_config(struct net_device *dev, unsigned int mode,
 			     const struct phylink_link_state *state);
+static void mvpp2_mac_link_up(struct net_device *dev, unsigned int mode,
+			      phy_interface_t interface, struct phy_device *phy);
 
 /* Queue modes */
 #define MVPP2_QDIST_SINGLE_MODE	0
@@ -3143,6 +3145,10 @@ static void mvpp2_start_dev(struct mvpp2_port *port)
 
 	if (port->phylink) {
 		phylink_start(port->phylink);
+
+		if (!(port->flags & MVPP2_F_FIXED_LINK))
+			mvpp2_mac_link_up(port->dev, MLO_AN_FIXED,
+					  port->phy_interface, NULL);
 	} else {
 		/* Phylink isn't used as of now for ACPI, so the MAC has to be
 		 * configured manually when the interface is started. This will
@@ -3150,9 +3156,10 @@ static void mvpp2_start_dev(struct mvpp2_port *port)
 		 */
 		struct phylink_link_state state = {
 			.interface = port->phy_interface,
-			.link = 1,
 		};
 		mvpp2_mac_config(port->dev, MLO_AN_INBAND, &state);
+		mvpp2_mac_link_up(port->dev, MLO_AN_INBAND, port->phy_interface,
+				  NULL);
 	}
 
 	netif_tx_start_all_queues(port->dev);
@@ -4495,10 +4502,6 @@ static void mvpp2_mac_config(struct net_device *dev, unsigned int mode,
 		return;
 	}
 
-	netif_tx_stop_all_queues(port->dev);
-	if (!port->has_phy)
-		netif_carrier_off(port->dev);
-
 	/* Make sure the port is disabled when reconfiguring the mode */
 	mvpp2_port_disable(port);
 
@@ -4523,16 +4526,7 @@ static void mvpp2_mac_config(struct net_device *dev, unsigned int mode,
 	if (port->priv->hw_version == MVPP21 && port->flags & MVPP2_F_LOOPBACK)
 		mvpp2_port_loopback_set(port, state);
 
-	/* If the port already was up, make sure it's still in the same state */
-	if (state->link || !port->has_phy) {
-		mvpp2_port_enable(port);
-
-		mvpp2_egress_enable(port);
-		mvpp2_ingress_enable(port);
-		if (!port->has_phy)
-			netif_carrier_on(dev);
-		netif_tx_wake_all_queues(dev);
-	}
+	mvpp2_port_enable(port);
 }
 
 static void mvpp2_mac_link_up(struct net_device *dev, unsigned int mode,
@@ -4691,6 +4685,9 @@ static int mvpp2_port_probe(struct platform_device *pdev,
 	if (fwnode_property_read_bool(port_fwnode, "marvell,loopback"))
 		port->flags |= MVPP2_F_LOOPBACK;
 
+	if (fwnode_property_present(port_fwnode, "fixed-link"))
+		port->flags |= MVPP2_F_FIXED_LINK;
+
 	port->id = id;
 	if (priv->hw_version == MVPP21)
 		port->first_rxq = port->id * port->nrxqs;
-- 
2.17.1