1 files changed, 41 insertions, 0 deletions
diff --git a/target/linux/generic/backport-5.4/791-net-phy-at803x-fix-probe-error-if-copper-page-is-sel.patch b/target/linux/generic/backport-5.4/791-net-phy-at803x-fix-probe-error-if-copper-page-is-sel.patch
new file mode 100644
index 0000000000..ac9583a89e
--- /dev/null
+++ b/target/linux/generic/backport-5.4/791-net-phy-at803x-fix-probe-error-if-copper-page-is-sel.patch
@@ -0,0 +1,41 @@
+From 8f7e876273e294b732b42af2e5e6bba91d798954 Mon Sep 17 00:00:00 2001
+From: Michael Walle <michael@walle.cc>
+Date: Tue, 20 Apr 2021 12:29:29 +0200
+Subject: [PATCH] net: phy: at803x: fix probe error if copper page is selected
+
+The commit c329e5afb42f ("net: phy: at803x: select correct page on
+config init") selects the copper page during probe. This fails if the
+copper page was already selected. In this case, the value of the copper
+page (which is 1) is propagated through phy_restore_page() and is
+finally returned for at803x_probe(). Fix it, by just using the
+at803x_page_write() directly.
+
+Also in case of an error, the regulator is not disabled and leads to a
+WARN_ON() when the probe fails. This couldn't happen before, because
+at803x_parse_dt() was the last call in at803x_probe(). It is hard to
+see, that the parse_dt() actually enables the regulator. Thus move the
+regulator_enable() to the probe function and undo it in case of an
+error.
+
+Fixes: c329e5afb42f ("net: phy: at803x: select correct page on config init")
+Signed-off-by: Michael Walle <michael@walle.cc>
+Reviewed-by: David Bauer <mail@david-bauer.net>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+---
+ drivers/net/phy/at803x.c | 23 +++++++++++++++++------
+ 1 file changed, 17 insertions(+), 6 deletions(-)
+
+--- a/drivers/net/phy/at803x.c
++++ b/drivers/net/phy/at803x.c
+@@ -289,8 +289,9 @@ static int at803x_probe(struct phy_devic
+ 	 * the PHY capabilities from the fiber side.
+ 	 */
+ 	if ((phydev->phy_id & phydev->drv->phy_id_mask) == (ATH8031_PHY_ID & phydev->drv->phy_id_mask)) {
+-		ret = phy_select_page(phydev, AT803X_PAGE_COPPER);
+-		ret = phy_restore_page(phydev, AT803X_PAGE_COPPER, ret);
++		mutex_lock(&phydev->mdio.bus->mdio_lock);
++		ret = at803x_write_page(phydev, AT803X_PAGE_COPPER);
++		mutex_unlock(&phydev->mdio.bus->mdio_lock);
+ 	}
+ 
+ 	return ret;