Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (67 commits)
  cxgb4vf: recover from failure in cxgb4vf_open()
  netfilter: ebtables: make broute table work again
  netfilter: fix race in conntrack between dump_table and destroy
  ah: reload pointers to skb data after calling skb_cow_data()
  ah: update maximum truncated ICV length
  xfrm: check trunc_len in XFRMA_ALG_AUTH_TRUNC
  ehea: Increase the skb array usage
  net/fec: remove config FEC2 as it's used nowhere
  pcnet_cs: add new_id
  tcp: disallow bind() to reuse addr/port
  net/r8169: Update the function of parsing firmware
  net: ppp: use {get,put}_unaligned_be{16,32}
  CAIF: Fix IPv6 support in receive path for GPRS/3G
  arp: allow to invalidate specific ARP entries
  net_sched: factorize qdisc stats handling
  mlx4: Call alloc_etherdev to allocate RX and TX queues
  net: Add alloc_netdev_mqs function
  caif: don't set connection request param size before copying data
  cxgb4vf: fix mailbox data/control coherency domain race
  qlcnic: change module parameter permissions
  ...

1 files changed, 11 insertions, 0 deletions

diff --git a/drivers/net/cxgb4vf/t4vf_hw.c b/drivers/net/cxgb4vf/t4vf_hw.c
index e4bec78c8e3f..0f51c80475ce 100644
--- a/drivers/net/cxgb4vf/t4vf_hw.c
+++ b/drivers/net/cxgb4vf/t4vf_hw.c
@@ -147,9 +147,20 @@ int t4vf_wr_mbox_core(struct adapter *adapter, const void *cmd, int size,
 	/*
 	 * Write the command array into the Mailbox Data register array and
 	 * transfer ownership of the mailbox to the firmware.
+	 *
+	 * For the VFs, the Mailbox Data "registers" are actually backed by
+	 * T4's "MA" interface rather than PL Registers (as is the case for
+	 * the PFs).  Because these are in different coherency domains, the
+	 * write to the VF's PL-register-backed Mailbox Control can race in
+	 * front of the writes to the MA-backed VF Mailbox Data "registers".
+	 * So we need to do a read-back on at least one byte of the VF Mailbox
+	 * Data registers before doing the write to the VF Mailbox Control
+	 * register.
 	 */
 	for (i = 0, p = cmd; i < size; i += 8)
 		t4_write_reg64(adapter, mbox_data + i, be64_to_cpu(*p++));
+	t4_read_reg(adapter, mbox_data);         /* flush write */
+
 	t4_write_reg(adapter, mbox_ctl,
 		     MBMSGVALID | MBOWNER(MBOX_OWNER_FW));
 	t4_read_reg(adapter, mbox_ctl);          /* flush write */