ixgbe: disable flow control by default

Since the adapter cannot tell what the remote end's flow control capability
is through auto-neg, we must turn off flow control by default.

Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

3 files changed, 26 insertions, 12 deletions

diff --git a/drivers/net/ixgbe/ixgbe.h b/drivers/net/ixgbe/ixgbe.h
index 956914a5028d..496a91aea63c 100644
--- a/drivers/net/ixgbe/ixgbe.h
+++ b/drivers/net/ixgbe/ixgbe.h
@@ -69,12 +69,12 @@
 
 /* flow control */
 #define IXGBE_DEFAULT_FCRTL             0x10000
-#define IXGBE_MIN_FCRTL                       0
+#define IXGBE_MIN_FCRTL                    0x40
 #define IXGBE_MAX_FCRTL                 0x7FF80
 #define IXGBE_DEFAULT_FCRTH             0x20000
-#define IXGBE_MIN_FCRTH                       0
+#define IXGBE_MIN_FCRTH                   0x600
 #define IXGBE_MAX_FCRTH                 0x7FFF0
-#define IXGBE_DEFAULT_FCPAUSE            0x6800  /* may be too long */
+#define IXGBE_DEFAULT_FCPAUSE            0xFFFF
 #define IXGBE_MIN_FCPAUSE                     0
 #define IXGBE_MAX_FCPAUSE                0xFFFF
 
diff --git a/drivers/net/ixgbe/ixgbe_common.c b/drivers/net/ixgbe/ixgbe_common.c
index a9f4d0e58e1c..9c0d0a1964eb 100644
--- a/drivers/net/ixgbe/ixgbe_common.c
+++ b/drivers/net/ixgbe/ixgbe_common.c
@@ -1065,6 +1065,13 @@ s32 ixgbe_setup_fc(struct ixgbe_hw *hw, s32 packetbuf_num)
         rmcs_reg &= ~(IXGBE_RMCS_TFCE_PRIORITY | IXGBE_RMCS_TFCE_802_3X);
 
         /*
+         * 10 gig parts do not have a word in the EEPROM to determine the
+         * default flow control setting, so we explicitly set it to full.
+         */
+        if (hw->fc.type == ixgbe_fc_default)
+                hw->fc.type = ixgbe_fc_full;
+
+        /*
          * We want to save off the original Flow Control configuration just in
          * case we get disconnected and then reconnected into a different hub
          * or switch with different Flow Control capabilities.
@@ -1117,6 +1124,16 @@ s32 ixgbe_setup_fc(struct ixgbe_hw *hw, s32 packetbuf_num)
         IXGBE_WRITE_REG(hw, IXGBE_RMCS, rmcs_reg);
 
         /*
+         * Check for invalid software configuration, zeros are completely
+         * invalid for all parameters used past this point, and if we enable
+         * flow control with zero water marks, we blast flow control packets.
+         */
+        if (!hw->fc.low_water || !hw->fc.high_water || !hw->fc.pause_time) {
+                hw_dbg(hw, "Flow control structure initialized incorrectly\n");
+                return IXGBE_ERR_INVALID_LINK_SETTINGS;
+        }
+
+        /*
          * We need to set up the Receive Threshold high and low water
          * marks as well as (optionally) enabling the transmission of
          * XON frames.
diff --git a/drivers/net/ixgbe/ixgbe_main.c b/drivers/net/ixgbe/ixgbe_main.c
index b5a9b9da2fb7..cba7a38bf6bb 100644
--- a/drivers/net/ixgbe/ixgbe_main.c
+++ b/drivers/net/ixgbe/ixgbe_main.c
@@ -2446,8 +2446,12 @@ static int __devinit ixgbe_sw_init(struct ixgbe_adapter *adapter)
         adapter->tx_eitr = 1;
 
         /* default flow control settings */
-        hw->fc.original_type = ixgbe_fc_full;
-        hw->fc.type = ixgbe_fc_full;
+        hw->fc.original_type = ixgbe_fc_none;
+        hw->fc.type = ixgbe_fc_none;
+        hw->fc.high_water = IXGBE_DEFAULT_FCRTH;
+        hw->fc.low_water = IXGBE_DEFAULT_FCRTL;
+        hw->fc.pause_time = IXGBE_DEFAULT_FCPAUSE;
+        hw->fc.send_xon = true;
 
         /* select 10G link by default */
         hw->mac.link_mode_select = IXGBE_AUTOC_LMS_10G_LINK_NO_AN;
@@ -3587,13 +3591,6 @@ static int __devinit ixgbe_probe(struct pci_dev *pdev,
 
         INIT_WORK(&adapter->reset_task, ixgbe_reset_task);
 
-        /* initialize default flow control settings */
-        hw->fc.original_type = ixgbe_fc_full;
-        hw->fc.type = ixgbe_fc_full;
-        hw->fc.high_water = IXGBE_DEFAULT_FCRTH;
-        hw->fc.low_water = IXGBE_DEFAULT_FCRTL;
-        hw->fc.pause_time = IXGBE_DEFAULT_FCPAUSE;
-
         err = ixgbe_init_interrupt_scheme(adapter);
         if (err)
                 goto err_sw_init;