net: bcmgenet: soft reset 40nm EPHYs before MAC init

It turns out that the "Workaround for putting the PHY in IDDQ mode"
used by the internal EPHYs on 40nm Set-Top Box chips when powering
down puts the interface to the GENET MAC in a state that can cause
subsequent MAC resets to be incomplete.

Rather than restore the forced soft reset when powering up internal
PHYs, this commit moves the invocation of phy_init_hw earlier in
the MAC initialization sequence to just before the MAC reset in the
open and resume functions. This allows the interface to be stable
and allows the MAC resets to be successful.

The bcmgenet_mii_probe() function is split in two to accommodate
this. The new function bcmgenet_mii_connect() handles the first
half of the functionality before the MAC initialization, and the
bcmgenet_mii_config() function is extended to provide the remaining
PHY configuration following the MAC initialization.

Fixes: 484bfa1507bf ("Revert "net: bcmgenet: Software reset EPHY after power on"")
Signed-off-by: Doug Berger <opendmb@gmail.com>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 17 insertions, 11 deletions

diff --git a/drivers/net/ethernet/broadcom/genet/bcmgenet.c b/drivers/net/ethernet/broadcom/genet/bcmgenet.c
index 10d68017ff6c..f0937c650e3c 100644
--- a/drivers/net/ethernet/broadcom/genet/bcmgenet.c
+++ b/drivers/net/ethernet/broadcom/genet/bcmgenet.c
@@ -2872,6 +2872,12 @@ static int bcmgenet_open(struct net_device *dev)
 	if (priv->internal_phy)
 		bcmgenet_power_up(priv, GENET_POWER_PASSIVE);
 
+	ret = bcmgenet_mii_connect(dev);
+	if (ret) {
+		netdev_err(dev, "failed to connect to PHY\n");
+		goto err_clk_disable;
+	}
+
 	/* take MAC out of reset */
 	bcmgenet_umac_reset(priv);
 
@@ -2881,6 +2887,12 @@ static int bcmgenet_open(struct net_device *dev)
 	reg = bcmgenet_umac_readl(priv, UMAC_CMD);
 	priv->crc_fwd_en = !!(reg & CMD_CRC_FWD);
 
+	ret = bcmgenet_mii_config(dev, true);
+	if (ret) {
+		netdev_err(dev, "unsupported PHY\n");
+		goto err_disconnect_phy;
+	}
+
 	bcmgenet_set_hw_addr(priv, dev->dev_addr);
 
 	if (priv->internal_phy) {
@@ -2896,7 +2908,7 @@ static int bcmgenet_open(struct net_device *dev)
 	ret = bcmgenet_init_dma(priv);
 	if (ret) {
 		netdev_err(dev, "failed to initialize DMA\n");
-		goto err_clk_disable;
+		goto err_disconnect_phy;
 	}
 
 	/* Always enable ring 16 - descriptor ring */
@@ -2919,25 +2931,19 @@ static int bcmgenet_open(struct net_device *dev)
 		goto err_irq0;
 	}
 
-	ret = bcmgenet_mii_probe(dev);
-	if (ret) {
-		netdev_err(dev, "failed to connect to PHY\n");
-		goto err_irq1;
-	}
-
 	bcmgenet_netif_start(dev);
 
 	netif_tx_start_all_queues(dev);
 
 	return 0;
 
-err_irq1:
-	free_irq(priv->irq1, priv);
 err_irq0:
 	free_irq(priv->irq0, priv);
 err_fini_dma:
 	bcmgenet_dma_teardown(priv);
 	bcmgenet_fini_dma(priv);
+err_disconnect_phy:
+	phy_disconnect(dev->phydev);
 err_clk_disable:
 	if (priv->internal_phy)
 		bcmgenet_power_down(priv, GENET_POWER_PASSIVE);
@@ -3618,6 +3624,8 @@ static int bcmgenet_resume(struct device *d)
 	if (priv->internal_phy)
 		bcmgenet_power_up(priv, GENET_POWER_PASSIVE);
 
+	phy_init_hw(dev->phydev);
+
 	bcmgenet_umac_reset(priv);
 
 	init_umac(priv);
@@ -3626,8 +3634,6 @@ static int bcmgenet_resume(struct device *d)
 	if (priv->wolopts)
 		clk_disable_unprepare(priv->clk_wol);
 
-	phy_init_hw(dev->phydev);
-
 	/* Speed settings must be restored */
 	bcmgenet_mii_config(priv->dev, false);