netdev - [PATCH] net: lan78xx: isolate LAN88XX specific operations

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Date:   Fri, 16 Dec 2022 15:49:11 +0100
From:   Enguerrand de Ribaucourt 
        <enguerrand.de-ribaucourt@...oirfairelinux.com>
To:     netdev@...r.kernel.org
Cc:     woojung.huh@...rochip.com, davem@...emloft.net,
        UNGLinuxDriver@...rochip.com,
        Enguerrand de Ribaucourt 
        <enguerrand.de-ribaucourt@...oirfairelinux.com>
Subject: [PATCH] net: lan78xx: isolate LAN88XX specific operations

Some operations during the cable switch workaround modify the register
LAN88XX_INT_MASK of the PHY. However, this register is specific to the
LAN8835 PHY. For instance, if a DP8322I PHY is connected to the LAN7801,
that register (0x19), corresponds to the LED and MAC address
configuration, resulting in unapropriate behavior.

Fixes: 14437e3fa284 ("lan78xx: workaround of forced 100 Full/Half duplex mode error")
Signed-off-by: Enguerrand de Ribaucourt <enguerrand.de-ribaucourt@...oirfairelinux.com>
---
 drivers/net/usb/lan78xx.c | 28 ++++++++++++++++++----------
 1 file changed, 18 insertions(+), 10 deletions(-)

diff --git a/drivers/net/usb/lan78xx.c b/drivers/net/usb/lan78xx.c
index f18ab8e220db..ea0a56e6cd40 100644
--- a/drivers/net/usb/lan78xx.c
+++ b/drivers/net/usb/lan78xx.c
@@ -2116,6 +2116,7 @@ static void lan78xx_link_status_change(struct net_device *net)
 {
 	struct phy_device *phydev = net->phydev;
 	int temp;
+	bool lan88_fixup;
 
 	/* At forced 100 F/H mode, chip may fail to set mode correctly
 	 * when cable is switched between long(~50+m) and short one.
@@ -2123,10 +2124,15 @@ static void lan78xx_link_status_change(struct net_device *net)
 	 * at forced 100 F/H mode.
 	 */
 	if (!phydev->autoneg && (phydev->speed == 100)) {
-		/* disable phy interrupt */
-		temp = phy_read(phydev, LAN88XX_INT_MASK);
-		temp &= ~LAN88XX_INT_MASK_MDINTPIN_EN_;
-		phy_write(phydev, LAN88XX_INT_MASK, temp);
+		lan88_fixup = (PHY_LAN8835 & 0xfffffff0) ==
+			(phydev->phy_id & 0xfffffff0);
+
+		if(lan88_fixup) {
+			/* disable phy interrupt */
+			temp = phy_read(phydev, LAN88XX_INT_MASK);
+			temp &= ~LAN88XX_INT_MASK_MDINTPIN_EN_;
+			phy_write(phydev, LAN88XX_INT_MASK, temp);
+		}
 
 		temp = phy_read(phydev, MII_BMCR);
 		temp &= ~(BMCR_SPEED100 | BMCR_SPEED1000);
@@ -2134,13 +2140,15 @@ static void lan78xx_link_status_change(struct net_device *net)
 		temp |= BMCR_SPEED100;
 		phy_write(phydev, MII_BMCR, temp); /* set to 100 later */
 
-		/* clear pending interrupt generated while workaround */
-		temp = phy_read(phydev, LAN88XX_INT_STS);
+		if(lan88_fixup) {
+			/* clear pending interrupt generated while workaround */
+			temp = phy_read(phydev, LAN88XX_INT_STS);
 
-		/* enable phy interrupt back */
-		temp = phy_read(phydev, LAN88XX_INT_MASK);
-		temp |= LAN88XX_INT_MASK_MDINTPIN_EN_;
-		phy_write(phydev, LAN88XX_INT_MASK, temp);
+			/* enable phy interrupt back */
+			temp = phy_read(phydev, LAN88XX_INT_MASK);
+			temp |= LAN88XX_INT_MASK_MDINTPIN_EN_;
+			phy_write(phydev, LAN88XX_INT_MASK, temp);
+		}
 	}
 }
 
-- 
2.25.1