[PATCH net-next v3 3/5] net: phy: mscc: Drop unnecessary phydev->lock

[Biju]

From: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>

Remove manual mutex_lock/unlock(&phydev->lock) calls from several
functions in the MSCC PHY driver.

In vsc85xx_edge_rate_cntl_set(), phydev->lock is taken around a single
phy_modify_paged() call. phy_modify_paged() is already a fully locked
atomic operation that acquires the MDIO bus lock internally, so the
additional phydev->lock is unnecessary.

The remaining three functions — vsc85xx_mac_if_set(),
vsc8531_pre_init_seq_set(), and vsc85xx_eee_init_seq_set() — use
phy_read(), phy_write(), phy_select_page(), and phy_restore_page(),
all of which operate under the MDIO bus lock. Taking phydev->lock
around them provides no additional serialisation.

Along with dropping the locks, error-path labels are renamed from
out_unlock to err or restore_oldpage to better reflect their purpose.
In vsc8531_pre_init_seq_set() and vsc85xx_eee_init_seq_set(), the
redundant intermediate assignment of oldpage before returning is also
eliminated.

No functional change intended.

Signed-off-by: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>
---
v2->v3:
 * Added the patch into series
 * Updated commit description.
v2:
 * New patch
---
 drivers/net/phy/mscc/mscc_main.c | 41 ++++++++++----------------------
 1 file changed, 12 insertions(+), 29 deletions(-)

diff --git a/drivers/net/phy/mscc/mscc_main.c b/drivers/net/phy/mscc/mscc_main.c
index 2b9fb8a675a6..75430f55acfd 100644
--- a/drivers/net/phy/mscc/mscc_main.c
+++ b/drivers/net/phy/mscc/mscc_main.c
@@ -486,15 +486,9 @@ static int vsc85xx_dt_led_modes_get(struct phy_device *phydev,
 
 static int vsc85xx_edge_rate_cntl_set(struct phy_device *phydev, u8 edge_rate)
 {
-	int rc;
-
-	mutex_lock(&phydev->lock);
-	rc = phy_modify_paged(phydev, MSCC_PHY_PAGE_EXTENDED_2,
-			      MSCC_PHY_WOL_MAC_CONTROL, EDGE_RATE_CNTL_MASK,
-			      edge_rate << EDGE_RATE_CNTL_POS);
-	mutex_unlock(&phydev->lock);
-
-	return rc;
+	return phy_modify_paged(phydev, MSCC_PHY_PAGE_EXTENDED_2,
+				MSCC_PHY_WOL_MAC_CONTROL, EDGE_RATE_CNTL_MASK,
+				edge_rate << EDGE_RATE_CNTL_POS);
 }
 
 static int vsc85xx_mac_if_set(struct phy_device *phydev,
@@ -503,7 +497,6 @@ static int vsc85xx_mac_if_set(struct phy_device *phydev,
 	int rc;
 	u16 reg_val;
 
-	mutex_lock(&phydev->lock);
 	reg_val = phy_read(phydev, MSCC_PHY_EXT_PHY_CNTL_1);
 	reg_val &= ~(MAC_IF_SELECTION_MASK);
 	switch (interface) {
@@ -522,17 +515,15 @@ static int vsc85xx_mac_if_set(struct phy_device *phydev,
 		break;
 	default:
 		rc = -EINVAL;
-		goto out_unlock;
+		goto err;
 	}
 	rc = phy_write(phydev, MSCC_PHY_EXT_PHY_CNTL_1, reg_val);
 	if (rc)
-		goto out_unlock;
+		goto err;
 
 	rc = genphy_soft_reset(phydev);
 
-out_unlock:
-	mutex_unlock(&phydev->lock);
-
+err:
 	return rc;
 }
 
@@ -668,19 +659,15 @@ static int vsc8531_pre_init_seq_set(struct phy_device *phydev)
 	if (rc < 0)
 		return rc;
 
-	mutex_lock(&phydev->lock);
 	oldpage = phy_select_page(phydev, MSCC_PHY_PAGE_TR);
 	if (oldpage < 0)
-		goto out_unlock;
+		goto restore_oldpage;
 
 	for (i = 0; i < ARRAY_SIZE(init_seq); i++)
 		vsc85xx_tr_write(phydev, init_seq[i].reg, init_seq[i].val);
 
-out_unlock:
-	oldpage = phy_restore_page(phydev, oldpage, oldpage);
-	mutex_unlock(&phydev->lock);
-
-	return oldpage;
+restore_oldpage:
+	return phy_restore_page(phydev, oldpage, oldpage);
 }
 
 static int vsc85xx_eee_init_seq_set(struct phy_device *phydev)
@@ -708,19 +695,15 @@ static int vsc85xx_eee_init_seq_set(struct phy_device *phydev)
 	unsigned int i;
 	int oldpage;
 
-	mutex_lock(&phydev->lock);
 	oldpage = phy_select_page(phydev, MSCC_PHY_PAGE_TR);
 	if (oldpage < 0)
-		goto out_unlock;
+		goto restore_oldpage;
 
 	for (i = 0; i < ARRAY_SIZE(init_eee); i++)
 		vsc85xx_tr_write(phydev, init_eee[i].reg, init_eee[i].val);
 
-out_unlock:
-	oldpage = phy_restore_page(phydev, oldpage, oldpage);
-	mutex_unlock(&phydev->lock);
-
-	return oldpage;
+restore_oldpage:
+	return phy_restore_page(phydev, oldpage, oldpage);
 }
 
 /* phydev->bus->mdio_lock should be locked when using this function */
-- 
2.43.0