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From:   Oleksij Rempel <o.rempel@pengutronix.de>
To:     "David S. Miller" <davem@davemloft.net>,
        Jakub Kicinski <kuba@kernel.org>, Andrew Lunn <andrew@lunn.ch>,
        Heiner Kallweit <hkallweit1@gmail.com>,
        Russell King <linux@armlinux.org.uk>
Cc:     Oleksij Rempel <o.rempel@pengutronix.de>,
        Marek Szyprowski <m.szyprowski@samsung.com>,
        Jon Hunter <jonathanh@nvidia.com>, kernel@pengutronix.de,
        linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org,
        netdev@vger.kernel.org
Subject: [PATCH v1 1/1] net: usb: asix: ax88772: manage PHY PM from MAC
Date:   Thu, 10 Jun 2021 16:20:09 +0200
Message-Id: <20210610142009.16162-1-o.rempel@pengutronix.de>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

Take over PHY power management, otherwise PHY framework will try to
access ASIX MDIO bus before MAC resume was completed.

Fixes: e532a096be0e ("net: usb: asix: ax88772: add phylib support")
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Reported-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reported-by: Jon Hunter <jonathanh@nvidia.com>
Suggested-by: Heiner Kallweit <hkallweit1@gmail.com>
---
 drivers/net/usb/asix_devices.c | 43 ++++++++++------------------------
 1 file changed, 12 insertions(+), 31 deletions(-)

diff --git a/drivers/net/usb/asix_devices.c b/drivers/net/usb/asix_devices.c
index 8a477171e8f5..aec97b021a73 100644
--- a/drivers/net/usb/asix_devices.c
+++ b/drivers/net/usb/asix_devices.c
@@ -598,6 +598,9 @@ static void ax88772_suspend(struct usbnet *dev)
 	struct asix_common_private *priv = dev->driver_priv;
 	u16 medium;
 
+	if (netif_running(dev->net))
+		phy_stop(priv->phydev);
+
 	/* Stop MAC operation */
 	medium = asix_read_medium_status(dev, 1);
 	medium &= ~AX_MEDIUM_RE;
@@ -605,14 +608,6 @@ static void ax88772_suspend(struct usbnet *dev)
 
 	netdev_dbg(dev->net, "ax88772_suspend: medium=0x%04x\n",
 		   asix_read_medium_status(dev, 1));
-
-	/* Preserve BMCR for restoring */
-	priv->presvd_phy_bmcr =
-		asix_mdio_read_nopm(dev->net, dev->mii.phy_id, MII_BMCR);
-
-	/* Preserve ANAR for restoring */
-	priv->presvd_phy_advertise =
-		asix_mdio_read_nopm(dev->net, dev->mii.phy_id, MII_ADVERTISE);
 }
 
 static int asix_suspend(struct usb_interface *intf, pm_message_t message)
@@ -626,39 +621,22 @@ static int asix_suspend(struct usb_interface *intf, pm_message_t message)
 	return usbnet_suspend(intf, message);
 }
 
-static void ax88772_restore_phy(struct usbnet *dev)
-{
-	struct asix_common_private *priv = dev->driver_priv;
-
-	if (priv->presvd_phy_advertise) {
-		/* Restore Advertisement control reg */
-		asix_mdio_write_nopm(dev->net, dev->mii.phy_id, MII_ADVERTISE,
-				     priv->presvd_phy_advertise);
-
-		/* Restore BMCR */
-		if (priv->presvd_phy_bmcr & BMCR_ANENABLE)
-			priv->presvd_phy_bmcr |= BMCR_ANRESTART;
-
-		asix_mdio_write_nopm(dev->net, dev->mii.phy_id, MII_BMCR,
-				     priv->presvd_phy_bmcr);
-
-		priv->presvd_phy_advertise = 0;
-		priv->presvd_phy_bmcr = 0;
-	}
-}
-
 static void ax88772_resume(struct usbnet *dev)
 {
+	struct asix_common_private *priv = dev->driver_priv;
 	int i;
 
 	for (i = 0; i < 3; i++)
 		if (!ax88772_hw_reset(dev, 1))
 			break;
-	ax88772_restore_phy(dev);
+
+	if (netif_running(dev->net))
+		phy_start(priv->phydev);
 }
 
 static void ax88772a_resume(struct usbnet *dev)
 {
+	struct asix_common_private *priv = dev->driver_priv;
 	int i;
 
 	for (i = 0; i < 3; i++) {
@@ -666,7 +644,8 @@ static void ax88772a_resume(struct usbnet *dev)
 			break;
 	}
 
-	ax88772_restore_phy(dev);
+	if (netif_running(dev->net))
+		phy_start(priv->phydev);
 }
 
 static int asix_resume(struct usb_interface *intf)
@@ -722,6 +701,8 @@ static int ax88772_init_phy(struct usbnet *dev)
 		return ret;
 	}
 
+	priv->phydev->mac_managed_pm = 1;
+
 	phy_attached_info(priv->phydev);
 
 	return 0;
-- 
2.29.2