From 98b9e48fca11c8aa54b25c02d3329392b52db8ab Mon Sep 17 00:00:00 2001 From: Greg Rose Date: Fri, 3 Jun 2011 03:53:24 +0000 Subject: [PATCH] ixgbevf: Check if EOP has changed before using it There is a chance that between the time EOP is read and the time it is used another transmit on a different CPU could have run and completed, thus leaving EOP in a bad state. Signed-off-by: Greg Rose Signed-off-by: Jeff Kirsher --- drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c b/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c index b1e1c2daf5f9..936532fa42ad 100644 --- a/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c +++ b/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c @@ -203,6 +203,9 @@ static bool ixgbevf_clean_tx_irq(struct ixgbevf_adapter *adapter, (count < tx_ring->work_limit)) { bool cleaned = false; rmb(); /* read buffer_info after eop_desc */ + /* eop could change between read and DD-check */ + if (unlikely(eop != tx_ring->tx_buffer_info[i].next_to_watch)) + goto cont_loop; for ( ; !cleaned; count++) { struct sk_buff *skb; tx_desc = IXGBE_TX_DESC_ADV(*tx_ring, i); @@ -232,6 +235,7 @@ static bool ixgbevf_clean_tx_irq(struct ixgbevf_adapter *adapter, i = 0; } +cont_loop: eop = tx_ring->tx_buffer_info[i].next_to_watch; eop_desc = IXGBE_TX_DESC_ADV(*tx_ring, eop); } -- 2.20.1