ixgbe: Update link setup code to better support autonegotiation of speed

The current code has some flaws in it when performing autonegotiation,
especially on KX/KX4 links.  This patch updates the code to better handle
the autonegotiation states on link setup.  The patch also removes a redundant
link configuration call on driver load, and moves link configuration to
the ->open() path.

Signed-off-by: Peter P Waskiewicz Jr <peter.p.waskiewicz.jr@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

4 files changed, 49 insertions, 80 deletions

diff --git a/drivers/net/ixgbe/ixgbe_82598.c b/drivers/net/ixgbe/ixgbe_82598.c
index 8e7315e0a7fa..f726a14d1a73 100644
--- a/drivers/net/ixgbe/ixgbe_82598.c
+++ b/drivers/net/ixgbe/ixgbe_82598.c
@@ -146,18 +146,12 @@ static s32 ixgbe_get_link_capabilities_82598(struct ixgbe_hw *hw,
                                              bool *autoneg)
 {
         s32 status = 0;
-        s32 autoc_reg;
 
-        autoc_reg = IXGBE_READ_REG(hw, IXGBE_AUTOC);
-
-        if (hw->mac.link_settings_loaded) {
-                autoc_reg &= ~IXGBE_AUTOC_LMS_ATTACH_TYPE;
-                autoc_reg &= ~IXGBE_AUTOC_LMS_MASK;
-                autoc_reg |= hw->mac.link_attach_type;
-                autoc_reg |= hw->mac.link_mode_select;
-        }
-
-        switch (autoc_reg & IXGBE_AUTOC_LMS_MASK) {
+        /*
+         * Determine link capabilities based on the stored value of AUTOC,
+         * which represents EEPROM defaults.
+         */
+        switch (hw->mac.orig_autoc & IXGBE_AUTOC_LMS_MASK) {
         case IXGBE_AUTOC_LMS_1G_LINK_NO_AN:
                 *speed = IXGBE_LINK_SPEED_1GB_FULL;
                 *autoneg = false;
@@ -176,9 +170,9 @@ static s32 ixgbe_get_link_capabilities_82598(struct ixgbe_hw *hw,
         case IXGBE_AUTOC_LMS_KX4_AN:
         case IXGBE_AUTOC_LMS_KX4_AN_1G_AN:
                 *speed = IXGBE_LINK_SPEED_UNKNOWN;
-                if (autoc_reg & IXGBE_AUTOC_KX4_SUPP)
+                if (hw->mac.orig_autoc & IXGBE_AUTOC_KX4_SUPP)
                         *speed |= IXGBE_LINK_SPEED_10GB_FULL;
-                if (autoc_reg & IXGBE_AUTOC_KX_SUPP)
+                if (hw->mac.orig_autoc & IXGBE_AUTOC_KX_SUPP)
                         *speed |= IXGBE_LINK_SPEED_1GB_FULL;
                 *autoneg = true;
                 break;
@@ -390,27 +384,17 @@ static s32 ixgbe_setup_mac_link_82598(struct ixgbe_hw *hw)
         u32 i;
         s32 status = 0;
 
-        autoc_reg = IXGBE_READ_REG(hw, IXGBE_AUTOC);
-
-        if (hw->mac.link_settings_loaded) {
-                autoc_reg &= ~IXGBE_AUTOC_LMS_ATTACH_TYPE;
-                autoc_reg &= ~IXGBE_AUTOC_LMS_MASK;
-                autoc_reg |= hw->mac.link_attach_type;
-                autoc_reg |= hw->mac.link_mode_select;
-
-                IXGBE_WRITE_REG(hw, IXGBE_AUTOC, autoc_reg);
-                IXGBE_WRITE_FLUSH(hw);
-                msleep(50);
-        }
-
         /* Restart link */
+        autoc_reg = IXGBE_READ_REG(hw, IXGBE_AUTOC);
         autoc_reg |= IXGBE_AUTOC_AN_RESTART;
         IXGBE_WRITE_REG(hw, IXGBE_AUTOC, autoc_reg);
 
         /* Only poll for autoneg to complete if specified to do so */
         if (hw->phy.autoneg_wait_to_complete) {
-                if (hw->mac.link_mode_select == IXGBE_AUTOC_LMS_KX4_AN ||
-                    hw->mac.link_mode_select == IXGBE_AUTOC_LMS_KX4_AN_1G_AN) {
+                if ((autoc_reg & IXGBE_AUTOC_LMS_MASK) ==
+                     IXGBE_AUTOC_LMS_KX4_AN ||
+                    (autoc_reg & IXGBE_AUTOC_LMS_MASK) ==
+                     IXGBE_AUTOC_LMS_KX4_AN_1G_AN) {
                         links_reg = 0; /* Just in case Autoneg time = 0 */
                         for (i = 0; i < IXGBE_AUTO_NEG_TIME; i++) {
                                 links_reg = IXGBE_READ_REG(hw, IXGBE_LINKS);
@@ -534,37 +518,43 @@ out:
  *  Set the link speed in the AUTOC register and restarts link.
  **/
 static s32 ixgbe_setup_mac_link_speed_82598(struct ixgbe_hw *hw,
-                                            ixgbe_link_speed speed, bool autoneg,
-                                            bool autoneg_wait_to_complete)
+                                           ixgbe_link_speed speed, bool autoneg,
+                                           bool autoneg_wait_to_complete)
 {
-        s32 status = 0;
+        s32              status            = 0;
+        ixgbe_link_speed link_capabilities = IXGBE_LINK_SPEED_UNKNOWN;
+        u32              curr_autoc        = IXGBE_READ_REG(hw, IXGBE_AUTOC);
+        u32              autoc             = curr_autoc;
+        u32              link_mode         = autoc & IXGBE_AUTOC_LMS_MASK;
 
-        /* If speed is 10G, then check for CX4 or XAUI. */
-        if ((speed == IXGBE_LINK_SPEED_10GB_FULL) &&
-            (!(hw->mac.link_attach_type & IXGBE_AUTOC_10G_KX4))) {
-                hw->mac.link_mode_select = IXGBE_AUTOC_LMS_10G_LINK_NO_AN;
-        } else if ((speed == IXGBE_LINK_SPEED_1GB_FULL) && (!autoneg)) {
-                hw->mac.link_mode_select = IXGBE_AUTOC_LMS_1G_LINK_NO_AN;
-        } else if (autoneg) {
-                /* BX mode - Autonegotiate 1G */
-                if (!(hw->mac.link_attach_type & IXGBE_AUTOC_1G_PMA_PMD))
-                        hw->mac.link_mode_select = IXGBE_AUTOC_LMS_1G_AN;
-                else /* KX/KX4 mode */
-                        hw->mac.link_mode_select = IXGBE_AUTOC_LMS_KX4_AN_1G_AN;
-        } else {
+        /* Check to see if speed passed in is supported. */
+        ixgbe_get_link_capabilities_82598(hw, &link_capabilities, &autoneg);
+        speed &= link_capabilities;
+
+        if (speed == IXGBE_LINK_SPEED_UNKNOWN)
                 status = IXGBE_ERR_LINK_SETUP;
+
+        /* Set KX4/KX support according to speed requested */
+        else if (link_mode == IXGBE_AUTOC_LMS_KX4_AN ||
+                 link_mode == IXGBE_AUTOC_LMS_KX4_AN_1G_AN) {
+                autoc &= ~IXGBE_AUTOC_KX4_KX_SUPP_MASK;
+                if (speed & IXGBE_LINK_SPEED_10GB_FULL)
+                        autoc |= IXGBE_AUTOC_KX4_SUPP;
+                if (speed & IXGBE_LINK_SPEED_1GB_FULL)
+                        autoc |= IXGBE_AUTOC_KX_SUPP;
+                if (autoc != curr_autoc)
+                        IXGBE_WRITE_REG(hw, IXGBE_AUTOC, autoc);
         }
 
         if (status == 0) {
                 hw->phy.autoneg_wait_to_complete = autoneg_wait_to_complete;
 
-                hw->mac.link_settings_loaded = true;
                 /*
                  * Setup and restart the link based on the new values in
                  * ixgbe_hw This will write the AUTOC register based on the new
                  * stored values
                  */
-                ixgbe_setup_mac_link_82598(hw);
+                status = ixgbe_setup_mac_link_82598(hw);
         }
 
         return status;
@@ -587,10 +577,6 @@ static s32 ixgbe_setup_copper_link_82598(struct ixgbe_hw *hw)
         /* Restart autonegotiation on PHY */
         status = hw->phy.ops.setup_link(hw);
 
-        /* Set MAC to KX/KX4 autoneg, which defaults to Parallel detection */
-        hw->mac.link_attach_type = (IXGBE_AUTOC_10G_KX4 | IXGBE_AUTOC_1G_KX);
-        hw->mac.link_mode_select = IXGBE_AUTOC_LMS_KX4_AN;
-
         /* Set up MAC */
         ixgbe_setup_mac_link_82598(hw);
 
@@ -617,10 +603,6 @@ static s32 ixgbe_setup_copper_link_speed_82598(struct ixgbe_hw *hw,
         status = hw->phy.ops.setup_link_speed(hw, speed, autoneg,
                                               autoneg_wait_to_complete);
 
-        /* Set MAC to KX/KX4 autoneg, which defaults to Parallel detection */
-        hw->mac.link_attach_type = (IXGBE_AUTOC_10G_KX4 | IXGBE_AUTOC_1G_KX);
-        hw->mac.link_mode_select = IXGBE_AUTOC_LMS_KX4_AN;
-
         /* Set up MAC */
         ixgbe_setup_mac_link_82598(hw);
 
@@ -720,24 +702,16 @@ static s32 ixgbe_reset_hw_82598(struct ixgbe_hw *hw)
         IXGBE_WRITE_REG(hw, IXGBE_GHECCR, gheccr);
 
         /*
-         * AUTOC register which stores link settings gets cleared
-         * and reloaded from EEPROM after reset. We need to restore
-         * our stored value from init in case SW changed the attach
-         * type or speed.  If this is the first time and link settings
-         * have not been stored, store default settings from AUTOC.
+         * Store the original AUTOC value if it has not been
+         * stored off yet.  Otherwise restore the stored original
+         * AUTOC value since the reset operation sets back to deaults.
          */
         autoc = IXGBE_READ_REG(hw, IXGBE_AUTOC);
-        if (hw->mac.link_settings_loaded) {
-                autoc &= ~(IXGBE_AUTOC_LMS_ATTACH_TYPE);
-                autoc &= ~(IXGBE_AUTOC_LMS_MASK);
-                autoc |= hw->mac.link_attach_type;
-                autoc |= hw->mac.link_mode_select;
-                IXGBE_WRITE_REG(hw, IXGBE_AUTOC, autoc);
-        } else {
-                hw->mac.link_attach_type =
-                                         (autoc & IXGBE_AUTOC_LMS_ATTACH_TYPE);
-                hw->mac.link_mode_select = (autoc & IXGBE_AUTOC_LMS_MASK);
-                hw->mac.link_settings_loaded = true;
+        if (hw->mac.orig_link_settings_stored == false) {
+                hw->mac.orig_autoc = autoc;
+                hw->mac.orig_link_settings_stored = true;
+        } else if (autoc != hw->mac.orig_autoc) {
+                IXGBE_WRITE_REG(hw, IXGBE_AUTOC, hw->mac.orig_autoc);
         }
 
         /* Store the permanent mac address */
diff --git a/drivers/net/ixgbe/ixgbe_common.c b/drivers/net/ixgbe/ixgbe_common.c
index 05f0e872947f..13ad5ba66b63 100644
--- a/drivers/net/ixgbe/ixgbe_common.c
+++ b/drivers/net/ixgbe/ixgbe_common.c
@@ -80,9 +80,6 @@ s32 ixgbe_start_hw_generic(struct ixgbe_hw *hw)
         /* Clear the VLAN filter table */
         hw->mac.ops.clear_vfta(hw);
 
-        /* Set up link */
-        hw->mac.ops.setup_link(hw);
-
         /* Clear statistics registers */
         hw->mac.ops.clear_hw_cntrs(hw);
 
diff --git a/drivers/net/ixgbe/ixgbe_main.c b/drivers/net/ixgbe/ixgbe_main.c
index d396c6e01fb5..5db82b5fa9b3 100644
--- a/drivers/net/ixgbe/ixgbe_main.c
+++ b/drivers/net/ixgbe/ixgbe_main.c
@@ -2799,9 +2799,6 @@ static int __devinit ixgbe_sw_init(struct ixgbe_adapter *adapter)
         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;
-
         /* enable itr by default in dynamic mode */
         adapter->itr_setting = 1;
         adapter->eitr_param = 20000;
diff --git a/drivers/net/ixgbe/ixgbe_type.h b/drivers/net/ixgbe/ixgbe_type.h
index c49ba8a17f1b..984b4ed372f1 100644
--- a/drivers/net/ixgbe/ixgbe_type.h
+++ b/drivers/net/ixgbe/ixgbe_type.h
@@ -721,6 +721,7 @@
 #define IXGBE_LED_OFF           0xF
 
 /* AUTOC Bit Masks */
+#define IXGBE_AUTOC_KX4_KX_SUPP_MASK 0xC0000000
 #define IXGBE_AUTOC_KX4_SUPP    0x80000000
 #define IXGBE_AUTOC_KX_SUPP     0x40000000
 #define IXGBE_AUTOC_PAUSE       0x30000000
@@ -1456,11 +1457,11 @@ struct ixgbe_mac_info {
         u32                             max_tx_queues;
         u32                             max_rx_queues;
         u32                             max_msix_vectors;
-        u32                             link_attach_type;
-        u32                             link_mode_select;
-        bool                            link_settings_loaded;
+        u32                             orig_autoc;
+        u32                             orig_autoc2;
+        bool                            orig_link_settings_stored;
         bool                            autoneg;
-        bool                            autoneg_failed;
+        bool                            autoneg_succeeded;
 };
 
 struct ixgbe_phy_info {