[PATCH net 2/2] e1000e: move force SMBUS from enable ulp function to avoid PHY loss issue

[Tony Nguyen <anthony.l.nguyen@intel.com>]

From: Vitaly Lifshits <vitaly.lifshits@intel.com>

Forcing SMBUS inside the ULP enabling flow leads to sporadic PHY loss on
some systems. It is suspected to be caused by initiating PHY transactions
before the interface settles.

Separating this configuration from the ULP enabling flow and moving it to
the shutdown function allows enough time for the interface to settle and
avoids adding a delay.

Fixes: 6607c99e7034 ("e1000e: i219 - fix to enable both ULP and EEE in Sx state")
Co-developed-by: Dima Ruinskiy <dima.ruinskiy@intel.com>
Signed-off-by: Dima Ruinskiy <dima.ruinskiy@intel.com>
Signed-off-by: Vitaly Lifshits <vitaly.lifshits@intel.com>
Tested-by: Naama Meir <naamax.meir@linux.intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
---
 drivers/net/ethernet/intel/e1000e/ich8lan.c | 19 -------------------
 drivers/net/ethernet/intel/e1000e/netdev.c  | 18 ++++++++++++++++++
 2 files changed, 18 insertions(+), 19 deletions(-)

diff --git a/drivers/net/ethernet/intel/e1000e/ich8lan.c b/drivers/net/ethernet/intel/e1000e/ich8lan.c
index d8e97669f31b..f9e94be36e97 100644
--- a/drivers/net/ethernet/intel/e1000e/ich8lan.c
+++ b/drivers/net/ethernet/intel/e1000e/ich8lan.c
@@ -1165,25 +1165,6 @@ s32 e1000_enable_ulp_lpt_lp(struct e1000_hw *hw, bool to_sx)
 	if (ret_val)
 		goto out;
 
-	/* Switching PHY interface always returns MDI error
-	 * so disable retry mechanism to avoid wasting time
-	 */
-	e1000e_disable_phy_retry(hw);
-
-	/* Force SMBus mode in PHY */
-	ret_val = e1000_read_phy_reg_hv_locked(hw, CV_SMB_CTRL, &phy_reg);
-	if (ret_val)
-		goto release;
-	phy_reg |= CV_SMB_CTRL_FORCE_SMBUS;
-	e1000_write_phy_reg_hv_locked(hw, CV_SMB_CTRL, phy_reg);
-
-	e1000e_enable_phy_retry(hw);
-
-	/* Force SMBus mode in MAC */
-	mac_reg = er32(CTRL_EXT);
-	mac_reg |= E1000_CTRL_EXT_FORCE_SMBUS;
-	ew32(CTRL_EXT, mac_reg);
-
 	/* Si workaround for ULP entry flow on i127/rev6 h/w.  Enable
 	 * LPLU and disable Gig speed when entering ULP
 	 */
diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c
index cc8c531ec3df..3692fce20195 100644
--- a/drivers/net/ethernet/intel/e1000e/netdev.c
+++ b/drivers/net/ethernet/intel/e1000e/netdev.c
@@ -6623,6 +6623,7 @@ static int __e1000_shutdown(struct pci_dev *pdev, bool runtime)
 	struct e1000_hw *hw = &adapter->hw;
 	u32 ctrl, ctrl_ext, rctl, status, wufc;
 	int retval = 0;
+	u16 smb_ctrl;
 
 	/* Runtime suspend should only enable wakeup for link changes */
 	if (runtime)
@@ -6696,6 +6697,23 @@ static int __e1000_shutdown(struct pci_dev *pdev, bool runtime)
 			if (retval)
 				return retval;
 		}
+
+		/* Force SMBUS to allow WOL */
+		/* Switching PHY interface always returns MDI error
+		 * so disable retry mechanism to avoid wasting time
+		 */
+		e1000e_disable_phy_retry(hw);
+
+		e1e_rphy(hw, CV_SMB_CTRL, &smb_ctrl);
+		smb_ctrl |= CV_SMB_CTRL_FORCE_SMBUS;
+		e1e_wphy(hw, CV_SMB_CTRL, smb_ctrl);
+
+		e1000e_enable_phy_retry(hw);
+
+		/* Force SMBus mode in MAC */
+		ctrl_ext = er32(CTRL_EXT);
+		ctrl_ext |= E1000_CTRL_EXT_FORCE_SMBUS;
+		ew32(CTRL_EXT, ctrl_ext);
 	}
 
 	/* Ensure that the appropriate bits are set in LPI_CTRL
-- 
2.41.0