igb: correctly offset 82575 flow control watermarks by 16 bytes

The watermark values for the 82575 were not being set correctly.  As a
result the high and low watermark values were set to the same value which
can lead to excess xon/xoff packets being generated.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/igb/igb_main.c b/drivers/net/igb/igb_main.c
index 78963a0..933c64f 100644 (file)
--- a/drivers/net/igb/igb_main.c
+++ b/drivers/net/igb/igb_main.c
@@ -1306,13 +1306,8 @@ void igb_reset(struct igb_adapter *adapter)
        hwm = min(((pba << 10) * 9 / 10),
                        ((pba << 10) - 2 * adapter->max_frame_size));
 
-       if (mac->type < e1000_82576) {
-               fc->high_water = hwm & 0xFFF8;  /* 8-byte granularity */
-               fc->low_water = fc->high_water - 8;
-       } else {
-               fc->high_water = hwm & 0xFFF0;  /* 16-byte granularity */
-               fc->low_water = fc->high_water - 16;
-       }
+       fc->high_water = hwm & 0xFFF0;  /* 16-byte granularity */
+       fc->low_water = fc->high_water - 16;
        fc->pause_time = 0xFFFF;
        fc->send_xon = 1;
        fc->current_mode = fc->requested_mode;