e1000: fix flow control thresholds

when testing the jumbo frames with pages patch, the stats would
show rx_missed errors (dropped packets) even when connected to a
link partner with flow control enabled.

this indicates that for this MTU (9000) the flow control
thresholds are not adjusting correctly.

In fact, before this change, the FCRTH (xoff threshold) is 36864
when the fifo size is only 40000, with 9000 byte MTU.

fix it so that we at least have room for one frame after we send
the xoff.

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>

1 files changed, 1 insertions, 1 deletions

diff --git a/drivers/net/e1000/e1000_hw.c b/drivers/net/e1000/e1000_hw.c
index e1a3fc1303ee..1e5ae112d57a 100644
--- a/drivers/net/e1000/e1000_hw.c
+++ b/drivers/net/e1000/e1000_hw.c
@@ -1955,7 +1955,7 @@ static s32 e1000_setup_copper_link(struct e1000_hw *hw)
     s32 ret_val;
     u16 i;
     u16 phy_data;
-    u16 reg_data;
+    u16 reg_data = 0;
 
     DEBUGFUNC("e1000_setup_copper_link");