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From:   Li Zhong <floridsleeves@gmail.com>
To:     netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
        intel-wired-lan@lists.osuosl.org
Cc:     jesse.brandeburg@intel.com, anthony.l.nguyen@intel.com,
        davem@davemloft.net, edumazet@google.com, kuba@kernel.org,
        pabeni@redhat.com, Li Zhong <floridsleeves@gmail.com>
Subject: [PATCH net-next v2] drivers/net/ethernet: check return value of e1e_rphy()
Date:   Thu, 25 Aug 2022 23:56:27 -0700
Message-Id: <20220826065627.1615965-1-floridsleeves@gmail.com>
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e1e_rphy() could return error value, which needs to be checked and
reported for debugging and diagnose.

Signed-off-by: Li Zhong <floridsleeves@gmail.com>
---
 drivers/net/ethernet/intel/e1000e/phy.c | 20 +++++++++++++++++---
 1 file changed, 17 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/intel/e1000e/phy.c b/drivers/net/ethernet/intel/e1000e/phy.c
index fd07c3679bb1..060b263348ce 100644
--- a/drivers/net/ethernet/intel/e1000e/phy.c
+++ b/drivers/net/ethernet/intel/e1000e/phy.c
@@ -2697,9 +2697,14 @@ static s32 e1000_access_phy_wakeup_reg_bm(struct e1000_hw *hw, u32 offset,
 void e1000_power_up_phy_copper(struct e1000_hw *hw)
 {
 	u16 mii_reg = 0;
+	int ret;
 
 	/* The PHY will retain its settings across a power down/up cycle */
-	e1e_rphy(hw, MII_BMCR, &mii_reg);
+	ret = e1e_rphy(hw, MII_BMCR, &mii_reg);
+	if (ret) {
+		e_dbg("Error reading PHY register\n");
+		return;
+	}
 	mii_reg &= ~BMCR_PDOWN;
 	e1e_wphy(hw, MII_BMCR, mii_reg);
 }
@@ -2715,9 +2720,14 @@ void e1000_power_up_phy_copper(struct e1000_hw *hw)
 void e1000_power_down_phy_copper(struct e1000_hw *hw)
 {
 	u16 mii_reg = 0;
+	int ret;
 
 	/* The PHY will retain its settings across a power down/up cycle */
-	e1e_rphy(hw, MII_BMCR, &mii_reg);
+	ret = e1e_rphy(hw, MII_BMCR, &mii_reg);
+	if (ret) {
+		e_dbg("Error reading PHY register\n");
+		return;
+	}
 	mii_reg |= BMCR_PDOWN;
 	e1e_wphy(hw, MII_BMCR, mii_reg);
 	usleep_range(1000, 2000);
@@ -3037,7 +3047,11 @@ s32 e1000_link_stall_workaround_hv(struct e1000_hw *hw)
 		return 0;
 
 	/* Do not apply workaround if in PHY loopback bit 14 set */
-	e1e_rphy(hw, MII_BMCR, &data);
+	ret_val = e1e_rphy(hw, MII_BMCR, &data);
+	if (ret_val) {
+		e_dbg("Error reading PHY register\n");
+		return ret_val;
+	}
 	if (data & BMCR_LOOPBACK)
 		return 0;
 
-- 
2.25.1