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authorJesse Brandeburg <jesse.brandeburg@intel.com>2010-04-27 01:37:41 +0000
committerDavid S. Miller <davem@davemloft.net>2010-04-27 12:53:28 -0700
commitef021194d262bdfa706dc5755596e252175a6bbc (patch)
tree4c5b3febfe32226173d08572d95a41693bbca712 /drivers/net/ixgbe/ixgbe_main.c
parentf8d1dcaf88bddc7f282722ec1fdddbcb06a72f18 (diff)
ixgbe: fix bug when EITR=0 causing no writebacks
writebacks can be held indefinitely by hardware if EITR=0, when combined with TXDCTL.WTHRESH=8. When EITR=0, WTHRESH should be set back to zero. Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com> Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/ixgbe/ixgbe_main.c')
-rw-r--r--drivers/net/ixgbe/ixgbe_main.c9
1 files changed, 7 insertions, 2 deletions
diff --git a/drivers/net/ixgbe/ixgbe_main.c b/drivers/net/ixgbe/ixgbe_main.c
index 0c4ca6822b7..fe7e260e015 100644
--- a/drivers/net/ixgbe/ixgbe_main.c
+++ b/drivers/net/ixgbe/ixgbe_main.c
@@ -2945,8 +2945,13 @@ static int ixgbe_up_complete(struct ixgbe_adapter *adapter)
for (i = 0; i < adapter->num_tx_queues; i++) {
j = adapter->tx_ring[i]->reg_idx;
txdctl = IXGBE_READ_REG(hw, IXGBE_TXDCTL(j));
- /* enable WTHRESH=8 descriptors, to encourage burst writeback */
- txdctl |= (8 << 16);
+ if (adapter->rx_itr_setting == 0) {
+ /* cannot set wthresh when itr==0 */
+ txdctl &= ~0x007F0000;
+ } else {
+ /* enable WTHRESH=8 descriptors, to encourage burst writeback */
+ txdctl |= (8 << 16);
+ }
IXGBE_WRITE_REG(hw, IXGBE_TXDCTL(j), txdctl);
}