[PATCH 4.9 037/177] net: bcmgenet: Power up the internal PHY before probing the MII

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Doug Berger <opendmb@xxxxxxxxx>


[ Upstream commit 6be371b053dc86f11465cc1abce2e99bda0a0574 ]

When using the internal PHY it must be powered up when the MII is probed
or the PHY will not be detected.  Since the PHY is powered up at reset
this has not been a problem.  However, when the kernel is restarted with
kexec the PHY will likely be powered down when the kernel starts so it
will not be detected and the Ethernet link will not be established.

This commit explicitly powers up the internal PHY when the GENET driver
is probed to correct this behavior.

Fixes: 1c1008c793fa ("net: bcmgenet: add main driver file")
Signed-off-by: Doug Berger <opendmb@xxxxxxxxx>
Reviewed-by: Florian Fainelli <f.fainelli@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/net/ethernet/broadcom/genet/bcmgenet.c |    8 ++++++++
 1 file changed, 8 insertions(+)

--- a/drivers/net/ethernet/broadcom/genet/bcmgenet.c
+++ b/drivers/net/ethernet/broadcom/genet/bcmgenet.c
@@ -3296,6 +3296,7 @@ static int bcmgenet_probe(struct platfor
 	const void *macaddr;
 	struct resource *r;
 	int err = -EIO;
+	const char *phy_mode_str;
 
 	/* Up to GENET_MAX_MQ_CNT + 1 TX queues and RX queues */
 	dev = alloc_etherdev_mqs(sizeof(*priv), GENET_MAX_MQ_CNT + 1,
@@ -3403,6 +3404,13 @@ static int bcmgenet_probe(struct platfor
 		priv->clk_eee = NULL;
 	}
 
+	/* If this is an internal GPHY, power it on now, before UniMAC is
+	 * brought out of reset as absolutely no UniMAC activity is allowed
+	 */
+	if (dn && !of_property_read_string(dn, "phy-mode", &phy_mode_str) &&
+	    !strcasecmp(phy_mode_str, "internal"))
+		bcmgenet_power_up(priv, GENET_POWER_PASSIVE);
+
 	err = reset_umac(priv);
 	if (err)
 		goto err_clk_disable;