ixgbe: DCB, misallocated packet buffer size with X540 device

The X540 device has a smaller packet buffer but the DCB configuration
never took this into account. Under stress this can result in the DMA
engine hanging and TX Unit hang occurring to reset the device. This
patch reworks the packet buffer allocation routine used for DCB on
82599 and X540 devices to account for RX packet buffer sizes.

This fixes the immediate hang. We should consolidate the various
hardware specific routines for configuring features into a single
routine. This will make it much harder to miss feature cases like
this.

Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Tested-by: Ross Brattain <ross.b.brattain@intel.com>
Tested-by: Evan Swanson <evan.swanson@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/drivers/net/ixgbe/ixgbe_82598.c b/drivers/net/ixgbe/ixgbe_82598.c
index af4054a1a133..7a64f50435cf 100644
--- a/drivers/net/ixgbe/ixgbe_82598.c
+++ b/drivers/net/ixgbe/ixgbe_82598.c
@@ -37,6 +37,7 @@
 #define IXGBE_82598_RAR_ENTRIES   16
 #define IXGBE_82598_MC_TBL_SIZE  128
 #define IXGBE_82598_VFT_TBL_SIZE 128
+#define IXGBE_82598_RX_PB_SIZE   512
 
 static s32 ixgbe_setup_copper_link_82598(struct ixgbe_hw *hw,
                                          ixgbe_link_speed speed,
@@ -224,6 +225,8 @@ static s32 ixgbe_start_hw_82598(struct ixgbe_hw *hw)
                 IXGBE_WRITE_REG(hw, IXGBE_DCA_RXCTRL(i), regval);
         }
 
+        hw->mac.rx_pb_size = IXGBE_82598_RX_PB_SIZE;
+
         /* set the completion timeout for interface */
         if (ret_val == 0)
                 ixgbe_set_pcie_completion_timeout(hw);