ixgbe: Harden the 82599 multispeed fiber autotry mechanism

82599 supports multispeed fiber optical modules (10Gbps/1Gbps).  Some
scenarios can cause the autotry mechanism to not negotiate link properly.
What needs to happen is the driver must flap the Tx laser to induce an Rx
Loss of Signal on the link partner.  This will restart the autotry
mechanism to get link into a known state.  The software definable pin (SDP)
3 on the 0x10fb NIC is wired to cause a Tx LOS event, which triggers the
Rx LOS we require.

Signed-off-by: Peter P Waskiewicz Jr <peter.p.waskiewicz.jr@intel.com>
Acked-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, 99 insertions, 21 deletions

diff --git a/drivers/net/ixgbe/ixgbe_82599.c b/drivers/net/ixgbe/ixgbe_82599.c
index a7611bbf387..84b83f7b473 100644
--- a/drivers/net/ixgbe/ixgbe_82599.c
+++ b/drivers/net/ixgbe/ixgbe_82599.c
@@ -461,12 +461,23 @@ s32 ixgbe_setup_mac_link_speed_multispeed_fiber(struct ixgbe_hw *hw,
 	u32 esdp_reg = IXGBE_READ_REG(hw, IXGBE_ESDP);
 	bool link_up = false;
 	bool negotiation;
+	int i;
 
 	/* Mask off requested but non-supported speeds */
 	hw->mac.ops.get_link_capabilities(hw, &phy_link_speed, &negotiation);
 	speed &= phy_link_speed;
 
 	/*
+	 * When the driver changes the link speeds that it can support,
+	 * it sets autotry_restart to true to indicate that we need to
+	 * initiate a new autotry session with the link partner.  To do
+	 * so, we set the speed then disable and re-enable the tx laser, to
+	 * alert the link partner that it also needs to restart autotry on its
+	 * end.  This is consistent with true clause 37 autoneg, which also
+	 * involves a loss of signal.
+	 */
+
+	/*
 	 * Try each speed one by one, highest priority first.  We do this in
 	 * software because 10gb fiber doesn't support speed autonegotiation.
 	 */
@@ -474,21 +485,52 @@ s32 ixgbe_setup_mac_link_speed_multispeed_fiber(struct ixgbe_hw *hw,
 		speedcnt++;
 		highest_link_speed = IXGBE_LINK_SPEED_10GB_FULL;
 
-		/* Set hardware SDP's */
+		/* If we already have link at this speed, just jump out */
+		hw->mac.ops.check_link(hw, &phy_link_speed, &link_up, false);
+
+		if ((phy_link_speed == IXGBE_LINK_SPEED_10GB_FULL) && link_up)
+			goto out;
+
+		/* Set the module link speed */
 		esdp_reg |= (IXGBE_ESDP_SDP5_DIR | IXGBE_ESDP_SDP5);
 		IXGBE_WRITE_REG(hw, IXGBE_ESDP, esdp_reg);
 
-		ixgbe_setup_mac_link_speed_82599(hw,
-		                                 IXGBE_LINK_SPEED_10GB_FULL,
-		                                 autoneg,
-		                                 autoneg_wait_to_complete);
-
-		msleep(50);
+		/* Allow module to change analog characteristics (1G->10G) */
+		msleep(40);
 
-		/* If we have link, just jump out */
-		hw->mac.ops.check_link(hw, &phy_link_speed, &link_up, false);
-		if (link_up)
+		status = ixgbe_setup_mac_link_speed_82599(hw,
+		                                     IXGBE_LINK_SPEED_10GB_FULL,
+		                                     autoneg,
+		                                     autoneg_wait_to_complete);
+		if (status != 0)
 			goto out;
+
+		/* Flap the tx laser if it has not already been done */
+		if (hw->mac.autotry_restart) {
+			/* Disable tx laser; allow 100us to go dark per spec */
+			esdp_reg |= IXGBE_ESDP_SDP3;
+			IXGBE_WRITE_REG(hw, IXGBE_ESDP, esdp_reg);
+			udelay(100);
+
+			/* Enable tx laser; allow 2ms to light up per spec */
+			esdp_reg &= ~IXGBE_ESDP_SDP3;
+			IXGBE_WRITE_REG(hw, IXGBE_ESDP, esdp_reg);
+			msleep(2);
+
+			hw->mac.autotry_restart = false;
+		}
+
+		/* The controller may take up to 500ms at 10g to acquire link */
+		for (i = 0; i < 5; i++) {
+			/* Wait for the link partner to also set speed */
+			msleep(100);
+
+			/* If we have link, just jump out */
+			hw->mac.ops.check_link(hw, &phy_link_speed,
+			                       &link_up, false);
+			if (link_up)
+				goto out;
+		}
 	}
 
 	if (speed & IXGBE_LINK_SPEED_1GB_FULL) {
@@ -496,16 +538,44 @@ s32 ixgbe_setup_mac_link_speed_multispeed_fiber(struct ixgbe_hw *hw,
 		if (highest_link_speed == IXGBE_LINK_SPEED_UNKNOWN)
 			highest_link_speed = IXGBE_LINK_SPEED_1GB_FULL;
 
-		/* Set hardware SDP's */
+		/* If we already have link at this speed, just jump out */
+		hw->mac.ops.check_link(hw, &phy_link_speed, &link_up, false);
+
+		if ((phy_link_speed == IXGBE_LINK_SPEED_1GB_FULL) && link_up)
+			goto out;
+
+		/* Set the module link speed */
 		esdp_reg &= ~IXGBE_ESDP_SDP5;
 		esdp_reg |= IXGBE_ESDP_SDP5_DIR;
 		IXGBE_WRITE_REG(hw, IXGBE_ESDP, esdp_reg);
 
-		ixgbe_setup_mac_link_speed_82599(
-			hw, IXGBE_LINK_SPEED_1GB_FULL, autoneg,
-			autoneg_wait_to_complete);
+		/* Allow module to change analog characteristics (10G->1G) */
+		msleep(40);
 
-		msleep(50);
+		status = ixgbe_setup_mac_link_speed_82599(hw,
+		                                      IXGBE_LINK_SPEED_1GB_FULL,
+		                                      autoneg,
+		                                      autoneg_wait_to_complete);
+		if (status != 0)
+			goto out;
+
+		/* Flap the tx laser if it has not already been done */
+		if (hw->mac.autotry_restart) {
+			/* Disable tx laser; allow 100us to go dark per spec */
+			esdp_reg |= IXGBE_ESDP_SDP3;
+			IXGBE_WRITE_REG(hw, IXGBE_ESDP, esdp_reg);
+			udelay(100);
+
+			/* Enable tx laser; allow 2ms to light up per spec */
+			esdp_reg &= ~IXGBE_ESDP_SDP3;
+			IXGBE_WRITE_REG(hw, IXGBE_ESDP, esdp_reg);
+			msleep(2);
+
+			hw->mac.autotry_restart = false;
+		}
+
+		/* Wait for the link partner to also set speed */
+		msleep(100);
 
 		/* If we have link, just jump out */
 		hw->mac.ops.check_link(hw, &phy_link_speed, &link_up, false);
@@ -591,6 +661,7 @@ s32 ixgbe_setup_mac_link_speed_82599(struct ixgbe_hw *hw,
 	s32 status = 0;
 	u32 autoc = IXGBE_READ_REG(hw, IXGBE_AUTOC);
 	u32 autoc2 = IXGBE_READ_REG(hw, IXGBE_AUTOC2);
+	u32 start_autoc = autoc;
 	u32 orig_autoc = 0;
 	u32 link_mode = autoc & IXGBE_AUTOC_LMS_MASK;
 	u32 pma_pmd_1g = autoc & IXGBE_AUTOC_1G_PMA_PMD_MASK;
@@ -603,6 +674,11 @@ s32 ixgbe_setup_mac_link_speed_82599(struct ixgbe_hw *hw,
 	hw->mac.ops.get_link_capabilities(hw, &link_capabilities, &autoneg);
 	speed &= link_capabilities;
 
+	if (speed == IXGBE_LINK_SPEED_UNKNOWN) {
+		status = IXGBE_ERR_LINK_SETUP;
+		goto out;
+	}
+
 	/* Use stored value (EEPROM defaults) of AUTOC to find KR/KX4 support*/
 	if (hw->mac.orig_link_settings_stored)
 		orig_autoc = hw->mac.orig_autoc;
@@ -610,11 +686,9 @@ s32 ixgbe_setup_mac_link_speed_82599(struct ixgbe_hw *hw,
 		orig_autoc = autoc;
 
 
-	if (speed == IXGBE_LINK_SPEED_UNKNOWN) {
-		status = IXGBE_ERR_LINK_SETUP;
-	} else if (link_mode == IXGBE_AUTOC_LMS_KX4_KX_KR ||
-	           link_mode == IXGBE_AUTOC_LMS_KX4_KX_KR_1G_AN ||
-	           link_mode == IXGBE_AUTOC_LMS_KX4_KX_KR_SGMII) {
+	if (link_mode == IXGBE_AUTOC_LMS_KX4_KX_KR ||
+	    link_mode == IXGBE_AUTOC_LMS_KX4_KX_KR_1G_AN ||
+	    link_mode == IXGBE_AUTOC_LMS_KX4_KX_KR_SGMII) {
 		/* Set KX4/KX/KR support according to speed requested */
 		autoc &= ~(IXGBE_AUTOC_KX4_KX_SUPP_MASK | IXGBE_AUTOC_KR_SUPP);
 		if (speed & IXGBE_LINK_SPEED_10GB_FULL)
@@ -646,7 +720,7 @@ s32 ixgbe_setup_mac_link_speed_82599(struct ixgbe_hw *hw,
 		}
 	}
 
-	if (status == 0) {
+	if (autoc != start_autoc) {
 		/* Restart link */
 		autoc |= IXGBE_AUTOC_AN_RESTART;
 		IXGBE_WRITE_REG(hw, IXGBE_AUTOC, autoc);
@@ -680,6 +754,7 @@ s32 ixgbe_setup_mac_link_speed_82599(struct ixgbe_hw *hw,
 		msleep(50);
 	}
 
+out:
 	return status;
 }
 
@@ -1144,6 +1219,9 @@ s32 ixgbe_start_hw_82599(struct ixgbe_hw *hw)
 	}
 	IXGBE_WRITE_FLUSH(hw);
 
+	/* We need to run link autotry after the driver loads */
+	hw->mac.autotry_restart = true;
+
 	return 0;
 }