ixgbe: Patch to modify 82598 PCIe completion timeout values

The default completion timeout values for 82598 should be in the
range of 50us to 50ms, however the hardware default for these
parts is 500us to 1ms which is less than the 10ms recommended by
the pcie spec. To address this we need to increase the value to
either 10ms to 250ms for capability version 1 configuration, or
16ms to 55ms for version 2.

Signed-off-by: Mallikarjuna R Chilakala <mallikarjuna.chilakala@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 66 insertions, 1 deletions

diff --git a/drivers/net/ixgbe/ixgbe_82598.c b/drivers/net/ixgbe/ixgbe_82598.c
index b9923047ce11..522c03bc1dad 100644
--- a/drivers/net/ixgbe/ixgbe_82598.c
+++ b/drivers/net/ixgbe/ixgbe_82598.c
@@ -50,6 +50,51 @@ static s32 ixgbe_read_i2c_eeprom_82598(struct ixgbe_hw *hw, u8 byte_offset,
                                        u8 *eeprom_data);
 
 /**
+ *  ixgbe_set_pcie_completion_timeout - set pci-e completion timeout
+ *  @hw: pointer to the HW structure
+ *
+ *  The defaults for 82598 should be in the range of 50us to 50ms,
+ *  however the hardware default for these parts is 500us to 1ms which is less
+ *  than the 10ms recommended by the pci-e spec.  To address this we need to
+ *  increase the value to either 10ms to 250ms for capability version 1 config,
+ *  or 16ms to 55ms for version 2.
+ **/
+void ixgbe_set_pcie_completion_timeout(struct ixgbe_hw *hw)
+{
+	struct ixgbe_adapter *adapter = hw->back;
+	u32 gcr = IXGBE_READ_REG(hw, IXGBE_GCR);
+	u16 pcie_devctl2;
+
+	/* only take action if timeout value is defaulted to 0 */
+	if (gcr & IXGBE_GCR_CMPL_TMOUT_MASK)
+		goto out;
+
+	/*
+	 * if capababilities version is type 1 we can write the
+	 * timeout of 10ms to 250ms through the GCR register
+	 */
+	if (!(gcr & IXGBE_GCR_CAP_VER2)) {
+		gcr |= IXGBE_GCR_CMPL_TMOUT_10ms;
+		goto out;
+	}
+
+	/*
+	 * for version 2 capabilities we need to write the config space
+	 * directly in order to set the completion timeout value for
+	 * 16ms to 55ms
+	 */
+	pci_read_config_word(adapter->pdev,
+	                     IXGBE_PCI_DEVICE_CONTROL2, &pcie_devctl2);
+	pcie_devctl2 |= IXGBE_PCI_DEVICE_CONTROL2_16ms;
+	pci_write_config_word(adapter->pdev,
+	                      IXGBE_PCI_DEVICE_CONTROL2, pcie_devctl2);
+out:
+	/* disable completion timeout resend */
+	gcr &= ~IXGBE_GCR_CMPL_TMOUT_RESEND;
+	IXGBE_WRITE_REG(hw, IXGBE_GCR, gcr);
+}
+
+/**
  *  ixgbe_get_pcie_msix_count_82598 - Gets MSI-X vector count
  *  @hw: pointer to hardware structure
  *
@@ -153,6 +198,26 @@ out:
 }
 
 /**
+ *  ixgbe_start_hw_82598 - Prepare hardware for Tx/Rx
+ *  @hw: pointer to hardware structure
+ *
+ *  Starts the hardware using the generic start_hw function.
+ *  Then set pcie completion timeout
+ **/
+s32 ixgbe_start_hw_82598(struct ixgbe_hw *hw)
+{
+	s32 ret_val = 0;
+
+	ret_val = ixgbe_start_hw_generic(hw);
+
+	/* set the completion timeout for interface */
+	if (ret_val == 0)
+		ixgbe_set_pcie_completion_timeout(hw);
+
+	return ret_val;
+}
+
+/**
  *  ixgbe_get_link_capabilities_82598 - Determines link capabilities
  *  @hw: pointer to hardware structure
  *  @speed: pointer to link speed
@@ -1085,7 +1150,7 @@ out:
 static struct ixgbe_mac_operations mac_ops_82598 = {
 	.init_hw		= &ixgbe_init_hw_generic,
 	.reset_hw		= &ixgbe_reset_hw_82598,
-	.start_hw		= &ixgbe_start_hw_generic,
+	.start_hw		= &ixgbe_start_hw_82598,
 	.clear_hw_cntrs		= &ixgbe_clear_hw_cntrs_generic,
 	.get_media_type		= &ixgbe_get_media_type_82598,
 	.get_supported_physical_layer = &ixgbe_get_supported_physical_layer_82598,