[PATCH v2 net-next] r8169: improve rtl_set_rx_mode

[Heiner Kallweit <hkallweit1@gmail.com>]

This patch improves and simplifies rtl_set_rx_mode a little.
No functional change intended.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
---
v2:
- change variable declarations to reverse xmas tree
---
 drivers/net/ethernet/realtek/r8169_main.c | 52 ++++++++++-------------
 1 file changed, 22 insertions(+), 30 deletions(-)

diff --git a/drivers/net/ethernet/realtek/r8169_main.c b/drivers/net/ethernet/realtek/r8169_main.c
index 9c743d2fc..9bd310938 100644
--- a/drivers/net/ethernet/realtek/r8169_main.c
+++ b/drivers/net/ethernet/realtek/r8169_main.c
@@ -61,7 +61,7 @@
 
 /* Maximum number of multicast addresses to filter (vs. Rx-all-multicast).
    The RTL chips use a 64 element hash table based on the Ethernet CRC. */
-static const int multicast_filter_limit = 32;
+#define	MC_FILTER_LIMIT	32
 
 #define TX_DMA_BURST	7	/* Maximum PCI burst, '7' is unlimited */
 #define InterFrameGap	0x03	/* 3 means InterFrameGap = the shortest one */
@@ -4146,54 +4146,46 @@ static void rtl8169_set_magic_reg(struct rtl8169_private *tp, unsigned mac_versi
 
 static void rtl_set_rx_mode(struct net_device *dev)
 {
+	u32 rx_mode = AcceptBroadcast | AcceptMyPhys | AcceptMulticast;
+	/* Multicast hash filter */
+	u32 mc_filter[2] = { 0xffffffff, 0xffffffff };
 	struct rtl8169_private *tp = netdev_priv(dev);
-	u32 mc_filter[2];	/* Multicast hash filter */
-	int rx_mode;
-	u32 tmp = 0;
+	u32 tmp;
 
 	if (dev->flags & IFF_PROMISC) {
 		/* Unconditionally log net taps. */
 		netif_notice(tp, link, dev, "Promiscuous mode enabled\n");
-		rx_mode =
-		    AcceptBroadcast | AcceptMulticast | AcceptMyPhys |
-		    AcceptAllPhys;
-		mc_filter[1] = mc_filter[0] = 0xffffffff;
-	} else if ((netdev_mc_count(dev) > multicast_filter_limit) ||
-		   (dev->flags & IFF_ALLMULTI)) {
-		/* Too many to filter perfectly -- accept all multicasts. */
-		rx_mode = AcceptBroadcast | AcceptMulticast | AcceptMyPhys;
-		mc_filter[1] = mc_filter[0] = 0xffffffff;
+		rx_mode |= AcceptAllPhys;
+	} else if (netdev_mc_count(dev) > MC_FILTER_LIMIT ||
+		   dev->flags & IFF_ALLMULTI ||
+		   tp->mac_version == RTL_GIGA_MAC_VER_35) {
+		/* accept all multicasts */
+	} else if (netdev_mc_empty(dev)) {
+		rx_mode &= ~AcceptMulticast;
 	} else {
 		struct netdev_hw_addr *ha;
 
-		rx_mode = AcceptBroadcast | AcceptMyPhys;
 		mc_filter[1] = mc_filter[0] = 0;
 		netdev_for_each_mc_addr(ha, dev) {
-			int bit_nr = ether_crc(ETH_ALEN, ha->addr) >> 26;
-			mc_filter[bit_nr >> 5] |= 1 << (bit_nr & 31);
-			rx_mode |= AcceptMulticast;
+			u32 bit_nr = ether_crc(ETH_ALEN, ha->addr) >> 26;
+			mc_filter[bit_nr >> 5] |= BIT(bit_nr & 31);
+		}
+
+		if (tp->mac_version > RTL_GIGA_MAC_VER_06) {
+			tmp = mc_filter[0];
+			mc_filter[0] = swab32(mc_filter[1]);
+			mc_filter[1] = swab32(tmp);
 		}
 	}
 
 	if (dev->features & NETIF_F_RXALL)
 		rx_mode |= (AcceptErr | AcceptRunt);
 
-	tmp = (RTL_R32(tp, RxConfig) & ~RX_CONFIG_ACCEPT_MASK) | rx_mode;
-
-	if (tp->mac_version > RTL_GIGA_MAC_VER_06) {
-		u32 data = mc_filter[0];
-
-		mc_filter[0] = swab32(mc_filter[1]);
-		mc_filter[1] = swab32(data);
-	}
-
-	if (tp->mac_version == RTL_GIGA_MAC_VER_35)
-		mc_filter[1] = mc_filter[0] = 0xffffffff;
-
 	RTL_W32(tp, MAR0 + 4, mc_filter[1]);
 	RTL_W32(tp, MAR0 + 0, mc_filter[0]);
 
-	RTL_W32(tp, RxConfig, tmp);
+	tmp = RTL_R32(tp, RxConfig);
+	RTL_W32(tp, RxConfig, (tmp & ~RX_CONFIG_ACCEPT_MASK) | rx_mode);
 }
 
 DECLARE_RTL_COND(rtl_csiar_cond)
-- 
2.22.0