1 files changed, 35 insertions, 0 deletions
diff --git a/target/linux/generic/pending-5.15/726-net-phy-realtek-make-sure-paged-read-is-protected-by.patch b/target/linux/generic/pending-5.15/726-net-phy-realtek-make-sure-paged-read-is-protected-by.patch
new file mode 100644
index 0000000000..31f0622327
--- /dev/null
+++ b/target/linux/generic/pending-5.15/726-net-phy-realtek-make-sure-paged-read-is-protected-by.patch
@@ -0,0 +1,35 @@
+From 4dd2cc9b91ecb25f278a2c55e07e6455e9000e6b Mon Sep 17 00:00:00 2001
+From: Daniel Golle <daniel@makrotopia.org>
+Date: Sat, 22 Apr 2023 01:21:14 +0100
+Subject: [PATCH] net: phy: realtek: make sure paged read is protected by mutex
+
+As we cannot rely on phy_read_paged function before the PHY is
+identified, the paged read in rtlgen_supports_2_5gbps needs to be open
+coded as it is being called by the match_phy_device function, ie. before
+.read_page and .write_page have been populated.
+
+Make sure it is also protected by the MDIO bus mutex and use
+rtl821x_write_page instead of 3 individually locked MDIO bus operations.
+
+Signed-off-by: Daniel Golle <daniel@makrotopia.org>
+---
+ drivers/net/phy/realtek.c | 8 +++++---
+ 1 file changed, 5 insertions(+), 3 deletions(-)
+
+--- a/drivers/net/phy/realtek.c
++++ b/drivers/net/phy/realtek.c
+@@ -727,9 +727,11 @@ static bool rtlgen_supports_2_5gbps(stru
+ {
+ 	int val;
+ 
+-	phy_write(phydev, RTL821x_PAGE_SELECT, 0xa61);
+-	val = phy_read(phydev, 0x13);
+-	phy_write(phydev, RTL821x_PAGE_SELECT, 0);
++	mutex_lock(&phydev->mdio.bus->mdio_lock);
++	rtl821x_write_page(phydev, 0xa61);
++	val = __phy_read(phydev, 0x13);
++	rtl821x_write_page(phydev, 0);
++	mutex_unlock(&phydev->mdio.bus->mdio_lock);
+ 
+ 	return val >= 0 && val & RTL_SUPPORTS_2500FULL;
+ }