dsa/mv88e6131: fix unknown multicast/broadcast forwarding on mv88e6085

The 88e6085 has a few differences from the other devices in the port
control registers, causing unknown multicast/broadcast packets to get
dropped when using the standard port setup.

At the same time update kconfig to clarify that the mv88e6085 is now
supported.
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>
Acked-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/dsa/Kconfig

@@ -41,12 +41,12 @@ config NET_DSA_MV88E6XXX_NEED_PPU
 	default n
 
 config NET_DSA_MV88E6131
-	bool "Marvell 88E6095/6095F/6131 ethernet switch chip support"
+	bool "Marvell 88E6085/6095/6095F/6131 ethernet switch chip support"
 	select NET_DSA_MV88E6XXX
 	select NET_DSA_MV88E6XXX_NEED_PPU
 	select NET_DSA_TAG_DSA
 	---help---
-	  This enables support for the Marvell 88E6095/6095F/6131
+	  This enables support for the Marvell 88E6085/6095/6095F/6131
 	  ethernet switch chips.
 
 config NET_DSA_MV88E6123_61_65

net/dsa/mv88e6131.c

@@ -207,8 +207,15 @@ static int mv88e6131_setup_port(struct dsa_switch *ds, int p)
 	 * mode, but do not enable forwarding of unknown unicasts.
 	 */
 	val = 0x0433;
-	if (p == dsa_upstream_port(ds))
+	if (p == dsa_upstream_port(ds)) {
 		val |= 0x0104;
+		/*
+		 * On 6085, unknown multicast forward is controlled
+		 * here rather than in Port Control 2 register.
+		 */
+		if (ps->id == ID_6085)
+			val |= 0x0008;
+	}
 	if (ds->dsa_port_mask & (1 << p))
 		val |= 0x0100;
 	REG_WRITE(addr, 0x04, val);
@@ -251,10 +258,19 @@ static int mv88e6131_setup_port(struct dsa_switch *ds, int p)
 	 * If this is the upstream port for this switch, enable
 	 * forwarding of unknown multicast addresses.
 	 */
+	if (ps->id == ID_6085)
+		/*
+		 * on 6085, bits 3:0 are reserved, bit 6 control ARP
+		 * mirroring, and multicast forward is handled in
+		 * Port Control register.
+		 */
+		REG_WRITE(addr, 0x08, 0x0080);
+	else {
 		val = 0x0080 | dsa_upstream_port(ds);
 		if (p == dsa_upstream_port(ds))
 			val |= 0x0040;
 		REG_WRITE(addr, 0x08, val);
+	}
 
 	/*
 	 * Rate Control: disable ingress rate limiting.