From bc1fc64fd2d9093496e5b04c6d94d26bfa629c9c Mon Sep 17 00:00:00 2001 From: Mark Rustad Date: Sat, 8 Aug 2015 16:27:51 -0700 Subject: [PATCH] ixgbe: Fix FCRTH value in VM-to-VM loopback mode The 82599 and X540 datasheets require that FCRTH be "set" for Tx switching (VM-to-VM loopback) but it did not previously specify what the value should be set to. It has now been determined that the correct value is RXPBSIZE - (24*1024). This setting is also required for later devices. Signed-off-by: Mark Rustad Signed-off-by: Jeff Kirsher --- drivers/net/ethernet/intel/ixgbe/ixgbe_common.c | 7 ++++--- drivers/net/ethernet/intel/ixgbe/ixgbe_dcb_82599.c | 8 +++++++- 2 files changed, 11 insertions(+), 4 deletions(-) diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_common.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_common.c index 98e1ddde3104..ce61b36b94f1 100644 --- a/drivers/net/ethernet/intel/ixgbe/ixgbe_common.c +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_common.c @@ -2164,10 +2164,11 @@ s32 ixgbe_fc_enable_generic(struct ixgbe_hw *hw) /* * In order to prevent Tx hangs when the internal Tx * switch is enabled we must set the high water mark - * to the maximum FCRTH value. This allows the Tx - * switch to function even under heavy Rx workloads. + * to the Rx packet buffer size - 24KB. This allows + * the Tx switch to function even under heavy Rx + * workloads. */ - fcrth = IXGBE_READ_REG(hw, IXGBE_RXPBSIZE(i)) - 32; + fcrth = IXGBE_READ_REG(hw, IXGBE_RXPBSIZE(i)) - 24576; } IXGBE_WRITE_REG(hw, IXGBE_FCRTH_82599(i), fcrth); diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_dcb_82599.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_dcb_82599.c index 3b932fe64ab6..23277ab153b6 100644 --- a/drivers/net/ethernet/intel/ixgbe/ixgbe_dcb_82599.c +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_dcb_82599.c @@ -259,7 +259,13 @@ s32 ixgbe_dcb_config_pfc_82599(struct ixgbe_hw *hw, u8 pfc_en, u8 *prio_tc) 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); } -- 2.20.1