sky2: accept multicast pause frames

When using flow control, the PHY needs to accept multicast pause frames.
Without this fix, these frames were getting discarded by the PHY before
doing any flow control.

Signed-off-by: Stephen Hemminger <shemminger@osdl.org>

drivers/net/sky2.c

@@ -2850,6 +2850,14 @@ static int sky2_set_mac_address(struct net_device *dev, void *p)
 	return 0;
 }
 
+static void inline sky2_add_filter(u8 filter[8], const u8 *addr)
+{
+	u32 bit;
+
+	bit = ether_crc(ETH_ALEN, addr) & 63;
+	filter[bit >> 3] |= 1 << (bit & 7);
+}
+
 static void sky2_set_multicast(struct net_device *dev)
 {
 	struct sky2_port *sky2 = netdev_priv(dev);
@@ -2858,26 +2866,30 @@ static void sky2_set_multicast(struct net_device *dev)
 	struct dev_mc_list *list = dev->mc_list;
 	u16 reg;
 	u8 filter[8];
+	int rx_pause;
+	static const u8 pause_mc_addr[ETH_ALEN] = { 0x1, 0x80, 0xc2, 0x0, 0x0, 0x1 };
 
+	rx_pause = (sky2->flow_status == FC_RX || sky2->flow_status == FC_BOTH);
 	memset(filter, 0, sizeof(filter));
 
 	reg = gma_read16(hw, port, GM_RX_CTRL);
 	reg |= GM_RXCR_UCF_ENA;
 
 	if (dev->flags & IFF_PROMISC)	/* promiscuous */
 		reg &= ~(GM_RXCR_UCF_ENA | GM_RXCR_MCF_ENA);
-	else if ((dev->flags & IFF_ALLMULTI) || dev->mc_count > 16)	/* all multicast */
+	else if (dev->flags & IFF_ALLMULTI)
 		memset(filter, 0xff, sizeof(filter));
-	else if (dev->mc_count == 0)	/* no multicast */
+	else if (dev->mc_count == 0 && !rx_pause)
 		reg &= ~GM_RXCR_MCF_ENA;
 	else {
 		int i;
 		reg |= GM_RXCR_MCF_ENA;
 
-		for (i = 0; list && i < dev->mc_count; i++, list = list->next) {
-			u32 bit = ether_crc(ETH_ALEN, list->dmi_addr) & 0x3f;
-			filter[bit / 8] |= 1 << (bit % 8);
-		}
+		if (rx_pause)
+			sky2_add_filter(filter, pause_mc_addr);
+
+		for (i = 0; list && i < dev->mc_count; i++, list = list->next)
+			sky2_add_filter(filter, list->dmi_addr);
 	}
 
 	gma_write16(hw, port, GM_MC_ADDR_H1,