e1000e: fix and commonize code for setting the receive address registers

Fix e1000e_rar_set() to flush consecutive register writes to avoid write
combining which some parts cannot handle.  Update e1000e_init_rx_addrs()
to call the fixed e1000e_rar_set() instead of duplicating code.

Also change e1000e_rar_set() to _not_ set the Address Valid bit if the MAC
address is all zeros.

Signed-off-by: Bruce Allan <bruce.w.allan@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 15 insertions, 9 deletions

diff --git a/drivers/net/e1000e/lib.c b/drivers/net/e1000e/lib.c
index 97649bf53b05..2fa9b36a2c5a 100644
--- a/drivers/net/e1000e/lib.c
+++ b/drivers/net/e1000e/lib.c
@@ -125,6 +125,7 @@ void e1000_write_vfta_generic(struct e1000_hw *hw, u32 offset, u32 value)
 void e1000e_init_rx_addrs(struct e1000_hw *hw, u16 rar_count)
 {
         u32 i;
+        u8 mac_addr[ETH_ALEN] = {0};
 
         /* Setup the receive address */
         e_dbg("Programming MAC Address into RAR[0]\n");
@@ -133,12 +134,8 @@ void e1000e_init_rx_addrs(struct e1000_hw *hw, u16 rar_count)
 
         /* Zero out the other (rar_entry_count - 1) receive addresses */
         e_dbg("Clearing RAR[1-%u]\n", rar_count-1);
-        for (i = 1; i < rar_count; i++) {
-                E1000_WRITE_REG_ARRAY(hw, E1000_RA, (i << 1), 0);
-                e1e_flush();
-                E1000_WRITE_REG_ARRAY(hw, E1000_RA, ((i << 1) + 1), 0);
-                e1e_flush();
-        }
+        for (i = 1; i < rar_count; i++)
+                e1000e_rar_set(hw, mac_addr, i);
 }
 
 /**
@@ -164,10 +161,19 @@ void e1000e_rar_set(struct e1000_hw *hw, u8 *addr, u32 index)
 
         rar_high = ((u32) addr[4] | ((u32) addr[5] << 8));
 
-        rar_high |= E1000_RAH_AV;
+        /* If MAC address zero, no need to set the AV bit */
+        if (rar_low || rar_high)
+                rar_high |= E1000_RAH_AV;
 
-        E1000_WRITE_REG_ARRAY(hw, E1000_RA, (index << 1), rar_low);
-        E1000_WRITE_REG_ARRAY(hw, E1000_RA, ((index << 1) + 1), rar_high);
+        /*
+         * Some bridges will combine consecutive 32-bit writes into
+         * a single burst write, which will malfunction on some parts.
+         * The flushes avoid this.
+         */
+        ew32(RAL(index), rar_low);
+        e1e_flush();
+        ew32(RAH(index), rar_high);
+        e1e_flush();
 }
 
 /**