From: Jian Shen <shenjian15@huawei.com>
Date: Sun, 14 Apr 2019 09:47:44 +0800
Subject: net: hns3: do not initialize MDIO bus when PHY is inexistent
Patch-mainline: v5.2-rc1
Git-commit: 2d0075b4a7b795bb6e6c4e392d36c023b0d0e858
References: bsc#1104353 FATE#326415 bsc#1135045

For some cases, PHY may not be connected to MDIO bus, then
the driver will initialize fail since MDIO bus initialization
fails.

This patch fixes it by skipping the MDIO bus initialization
when PHY is inexistent.

Signed-off-by: Jian Shen <shenjian15@huawei.com>
Signed-off-by: Peng Li <lipeng321@huawei.com>
Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_mdio.c |    8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

--- a/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_mdio.c
+++ b/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_mdio.c
@@ -129,12 +129,18 @@ static int hclge_mdio_read(struct mii_bu
 
 int hclge_mac_mdio_config(struct hclge_dev *hdev)
 {
+#define PHY_INEXISTENT	255
+
 	struct hclge_mac *mac = &hdev->hw.mac;
 	struct phy_device *phydev;
 	struct mii_bus *mdio_bus;
 	int ret;
 
-	if (hdev->hw.mac.phy_addr >= PHY_MAX_ADDR) {
+	if (hdev->hw.mac.phy_addr == PHY_INEXISTENT) {
+		dev_info(&hdev->pdev->dev,
+			 "no phy device is connected to mdio bus\n");
+		return 0;
+	} else if (hdev->hw.mac.phy_addr >= PHY_MAX_ADDR) {
 		dev_err(&hdev->pdev->dev, "phy_addr(%d) is too large.\n",
 			hdev->hw.mac.phy_addr);
 		return -EINVAL;