e1000e: fix flow-control thresholds for jumbo frames on 82579/I217/I218
The previous static flow-control thresholds were causing unnecessary pause
packets to be transmitted when jumbo frames are configured reducing the
throughput.
Signed-off-by: Bruce Allan <bruce.w.allan@intel.com>
Tested-by: Jeff Pieper <jeffrey.e.pieper@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c
index c15b7e4..8bb5d28 100644
--- a/drivers/net/ethernet/intel/e1000e/netdev.c
+++ b/drivers/net/ethernet/intel/e1000e/netdev.c
@@ -3724,14 +3724,17 @@
break;
case e1000_pch2lan:
case e1000_pch_lpt:
- fc->high_water = 0x05C20;
- fc->low_water = 0x05048;
- fc->pause_time = 0x0650;
fc->refresh_time = 0x0400;
- if (adapter->netdev->mtu > ETH_DATA_LEN) {
- pba = 14;
- ew32(PBA, pba);
+
+ if (adapter->netdev->mtu <= ETH_DATA_LEN) {
+ fc->high_water = 0x05C20;
+ fc->low_water = 0x05048;
+ fc->pause_time = 0x0650;
+ break;
}
+
+ fc->high_water = ((pba << 10) * 9 / 10) & E1000_FCRTH_RTH;
+ fc->low_water = ((pba << 10) * 8 / 10) & E1000_FCRTL_RTL;
break;
}