net: mvpp2: do not disable GMAC padding

commit e749aca upstream.

Short fragmented packets may never be sent by the hardware when padding
is disabled. This patch stop modifying the GMAC padding bits, to leave
them to their reset value (disabled).

Fixes: 3919357 ("net: mvpp2: initialize the GMAC when using a port")
Signed-off-by: Yan Markman <ymarkman@marvell.com>
[Antoine: commit message]
Signed-off-by: Antoine Tenart <antoine.tenart@free-electrons.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: yanmarkman

drivers/net/ethernet/marvell/mvpp2.c

@@ -4552,22 +4552,13 @@ static void mvpp2_port_mii_gmac_configure_mode(struct mvpp2_port *port)
 		       MVPP22_CTRL4_QSGMII_BYPASS_ACTIVE;
 		val &= ~MVPP22_CTRL4_EXT_PIN_GMII_SEL;
 		writel(val, port->base + MVPP22_GMAC_CTRL_4_REG);
-
-		val = readl(port->base + MVPP2_GMAC_CTRL_2_REG);
-		val |= MVPP2_GMAC_DISABLE_PADDING;
-		val &= ~MVPP2_GMAC_FLOW_CTRL_MASK;
-		writel(val, port->base + MVPP2_GMAC_CTRL_2_REG);
 	} else if (phy_interface_mode_is_rgmii(port->phy_interface)) {
 		val = readl(port->base + MVPP22_GMAC_CTRL_4_REG);
 		val |= MVPP22_CTRL4_EXT_PIN_GMII_SEL |
 		       MVPP22_CTRL4_SYNC_BYPASS_DIS |
 		       MVPP22_CTRL4_QSGMII_BYPASS_ACTIVE;
 		val &= ~MVPP22_CTRL4_DP_CLK_SEL;
 		writel(val, port->base + MVPP22_GMAC_CTRL_4_REG);
-
-		val = readl(port->base + MVPP2_GMAC_CTRL_2_REG);
-		val &= ~MVPP2_GMAC_DISABLE_PADDING;
-		writel(val, port->base + MVPP2_GMAC_CTRL_2_REG);
 	}
 
 	/* The port is connected to a copper PHY */