From 81c522851436dbc058c9c0c11b32e60d76b180ce Mon Sep 17 00:00:00 2001 From: Jesse Brandeburg Date: Sat, 4 Apr 2009 16:36:53 -0700 Subject: [PATCH] e1000: fix loss of multicast packets e1000 (and e1000e, igb, ixgbe, ixgb) all do a series of operations each time a multicast address is added. The flow goes something like 1) stack adds one multicast address 2) stack passes whole current list of unicast and multicast addresses to driver 3) driver clears entire list in hardware 4) driver programs each multicast address using iomem in a loop This was causing multicast packets to be lost during the reprogramming process. reference with test program: http://kerneltrap.org/mailarchive/linux-netdev/2009/3/14/5160514/thread Thanks to Dave Boutcher for his report and test program. This driver fix prepares an array all at once in memory and programs it in one shot to the hardware, not requiring an "erase" cycle. Signed-off-by: Jesse Brandeburg Signed-off-by: Jeff Kirsher Signed-off-by: David S. Miller --- drivers/net/e1000/e1000_main.c | 34 ++++++++++++++++++++++++++-------- 1 file changed, 26 insertions(+), 8 deletions(-) diff --git a/drivers/net/e1000/e1000_main.c b/drivers/net/e1000/e1000_main.c index 93b861d032b5..a65023d772cb 100644 --- a/drivers/net/e1000/e1000_main.c +++ b/drivers/net/e1000/e1000_main.c @@ -2335,6 +2335,12 @@ static void e1000_set_rx_mode(struct net_device *netdev) int mta_reg_count = (hw->mac_type == e1000_ich8lan) ? E1000_NUM_MTA_REGISTERS_ICH8LAN : E1000_NUM_MTA_REGISTERS; + u32 *mcarray = kcalloc(mta_reg_count, sizeof(u32), GFP_ATOMIC); + + if (!mcarray) { + DPRINTK(PROBE, ERR, "memory allocation failed\n"); + return; + } if (hw->mac_type == e1000_ich8lan) rar_entries = E1000_RAR_ENTRIES_ICH8LAN; @@ -2401,22 +2407,34 @@ static void e1000_set_rx_mode(struct net_device *netdev) } WARN_ON(uc_ptr != NULL); - /* clear the old settings from the multicast hash table */ - - for (i = 0; i < mta_reg_count; i++) { - E1000_WRITE_REG_ARRAY(hw, MTA, i, 0); - E1000_WRITE_FLUSH(); - } - /* load any remaining addresses into the hash table */ for (; mc_ptr; mc_ptr = mc_ptr->next) { + u32 hash_reg, hash_bit, mta; hash_value = e1000_hash_mc_addr(hw, mc_ptr->da_addr); - e1000_mta_set(hw, hash_value); + hash_reg = (hash_value >> 5) & 0x7F; + hash_bit = hash_value & 0x1F; + mta = (1 << hash_bit); + mcarray[hash_reg] |= mta; } + /* write the hash table completely, write from bottom to avoid + * both stupid write combining chipsets, and flushing each write */ + for (i = mta_reg_count - 1; i >= 0 ; i--) { + /* + * If we are on an 82544 has an errata where writing odd + * offsets overwrites the previous even offset, but writing + * backwards over the range solves the issue by always + * writing the odd offset first + */ + E1000_WRITE_REG_ARRAY(hw, MTA, i, mcarray[i]); + } + E1000_WRITE_FLUSH(); + if (hw->mac_type == e1000_82542_rev2_0) e1000_leave_82542_rst(adapter); + + kfree(mcarray); } /* Need to wait a few seconds after link up to get diagnostic information from -- 2.20.1