net: mvpp2: disable force link UP during port init procedure

Force link UP can be enabled by bootloader during tftpboot
and breaks NFS support.
Force link UP disabled during port init procedure.

Fixes: f84bf386 ("net: mvpp2: initialize the GoP")
Signed-off-by: Stefan Chulski <stefanc@marvell.com>
Acked-by: Marcin Wojtas <mw@semihalf.com>
Link: https://lore.kernel.org/r/1608216735-14501-1-git-send-email-stefanc@marvell.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c

@@ -5487,7 +5487,7 @@ static int mvpp2_port_init(struct mvpp2_port *port)
 	struct mvpp2 *priv = port->priv;
 	struct mvpp2_txq_pcpu *txq_pcpu;
 	unsigned int thread;
-	int queue, err;
+	int queue, err, val;
 
 	/* Checks for hardware constraints */
 	if (port->first_rxq + port->nrxqs >
@@ -5501,6 +5501,18 @@ static int mvpp2_port_init(struct mvpp2_port *port)
 	mvpp2_egress_disable(port);
 	mvpp2_port_disable(port);
 
+	if (mvpp2_is_xlg(port->phy_interface)) {
+		val = readl(port->base + MVPP22_XLG_CTRL0_REG);
+		val &= ~MVPP22_XLG_CTRL0_FORCE_LINK_PASS;
+		val |= MVPP22_XLG_CTRL0_FORCE_LINK_DOWN;
+		writel(val, port->base + MVPP22_XLG_CTRL0_REG);
+	} else {
+		val = readl(port->base + MVPP2_GMAC_AUTONEG_CONFIG);
+		val &= ~MVPP2_GMAC_FORCE_LINK_PASS;
+		val |= MVPP2_GMAC_FORCE_LINK_DOWN;
+		writel(val, port->base + MVPP2_GMAC_AUTONEG_CONFIG);
+	}
+
 	port->tx_time_coal = MVPP2_TXDONE_COAL_USEC;
 
 	port->txqs = devm_kcalloc(dev, port->ntxqs, sizeof(*port->txqs),