net: bcmgenet: correct MIB access of UniMAC RUNT counters

BugLink: http://bugs.launchpad.net/bugs/1745052

[ Upstream commit 1ad3d225 ]

The gap between the Tx status counters and the Rx RUNT counters is now
being added to allow correct reporting of the registers.

Fixes: 1c1008c7 ("net: bcmgenet: add main driver file")
Signed-off-by: Doug Berger <opendmb@gmail.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>

drivers/net/ethernet/broadcom/genet/bcmgenet.c

@@ -876,13 +876,16 @@ static void bcmgenet_update_mib_counters(struct bcmgenet_priv *priv)
 		case BCMGENET_STAT_NETDEV:
 		case BCMGENET_STAT_SOFT:
 			continue;
-		case BCMGENET_STAT_MIB_RX:
-		case BCMGENET_STAT_MIB_TX:
 		case BCMGENET_STAT_RUNT:
-			if (s->type != BCMGENET_STAT_MIB_RX)
-				offset = BCMGENET_STAT_OFFSET;
+			offset += BCMGENET_STAT_OFFSET;
+			/* fall through */
+		case BCMGENET_STAT_MIB_TX:
+			offset += BCMGENET_STAT_OFFSET;
+			/* fall through */
+		case BCMGENET_STAT_MIB_RX:
 			val = bcmgenet_umac_readl(priv,
 						  UMAC_MIB_START + j + offset);
+			offset = 0;	/* Reset Offset */
 			break;
 		case BCMGENET_STAT_MISC:
 			if (GENET_IS_V1(priv)) {