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, 0 insertions, 3 deletions

diff --git a/drivers/net/e1000/e1000_hw.h b/drivers/net/e1000/e1000_hw.h
index 99fce2c5dd26..a8866bdbb671 100644
--- a/drivers/net/e1000/e1000_hw.h
+++ b/drivers/net/e1000/e1000_hw.h
@@ -523,11 +523,8 @@ s32 e1000_check_phy_reset_block(struct e1000_hw *hw);
 
 /* The sizes (in bytes) of a ethernet packet */
 #define ENET_HEADER_SIZE             14
-#define MAXIMUM_ETHERNET_FRAME_SIZE  1518 /* With FCS */
 #define MINIMUM_ETHERNET_FRAME_SIZE  64   /* With FCS */
 #define ETHERNET_FCS_SIZE            4
-#define MAXIMUM_ETHERNET_PACKET_SIZE \
-    (MAXIMUM_ETHERNET_FRAME_SIZE - ETHERNET_FCS_SIZE)
 #define MINIMUM_ETHERNET_PACKET_SIZE \
     (MINIMUM_ETHERNET_FRAME_SIZE - ETHERNET_FCS_SIZE)
 #define CRC_LENGTH                   ETHERNET_FCS_SIZE