ixgbe/base: rework flow control

[dpdk.git] / lib / librte_pmd_ixgbe / ixgbe / ixgbe_dcb_82599.c

diff --git a/lib/librte_pmd_ixgbe/ixgbe/ixgbe_dcb_82599.c b/lib/librte_pmd_ixgbe/ixgbe/ixgbe_dcb_82599.c
index cc7ce7a..5075e4f 100644 (file)
--- a/lib/librte_pmd_ixgbe/ixgbe/ixgbe_dcb_82599.c
+++ b/lib/librte_pmd_ixgbe/ixgbe/ixgbe_dcb_82599.c
@@ -329,7 +329,14 @@ s32 ixgbe_dcb_config_pfc_82599(struct ixgbe_hw *hw, u8 pfc_en, u8 *map)
                        fcrtl = (hw->fc.low_water[i] << 10) | IXGBE_FCRTL_XONE;
                        IXGBE_WRITE_REG(hw, IXGBE_FCRTL_82599(i), fcrtl);
                } else {
-                       reg = IXGBE_READ_REG(hw, IXGBE_RXPBSIZE(i)) - 32;
+                       /*
+                        * In order to prevent Tx hangs when the internal Tx
+                        * switch is enabled we must set the high water mark
+                        * to the Rx packet buffer size - 24KB.  This allows
+                        * the Tx switch to function even under heavy Rx
+                        * workloads.
+                        */
+                       reg = IXGBE_READ_REG(hw, IXGBE_RXPBSIZE(i)) - 24576;
                        IXGBE_WRITE_REG(hw, IXGBE_FCRTL_82599(i), 0);
                }