[PATCH AUTOSEL 5.4 087/187] net: usb: lan78xx: Fix suspend/resume PHY register access error

From: Sasha Levin
Date: Fri Dec 27 2019 - 12:42:53 EST


From: Cristian Birsan <cristian.birsan@xxxxxxxxxxxxx>

[ Upstream commit 20032b63586ac6c28c936dff696981159913a13f ]

Lan78xx driver accesses the PHY registers through MDIO bus over USB
connection. When performing a suspend/resume, the PHY registers can be
accessed before the USB connection is resumed. This will generate an
error and will prevent the device to resume correctly.
This patch adds the dependency between the MDIO bus and USB device to
allow correct handling of suspend/resume.

Fixes: ce85e13ad6ef ("lan78xx: Update to use phylib instead of mii_if_info.")
Signed-off-by: Cristian Birsan <cristian.birsan@xxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/net/usb/lan78xx.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/drivers/net/usb/lan78xx.c b/drivers/net/usb/lan78xx.c
index f24a1b0b801f..0becc79fd431 100644
--- a/drivers/net/usb/lan78xx.c
+++ b/drivers/net/usb/lan78xx.c
@@ -1808,6 +1808,7 @@ static int lan78xx_mdio_init(struct lan78xx_net *dev)
dev->mdiobus->read = lan78xx_mdiobus_read;
dev->mdiobus->write = lan78xx_mdiobus_write;
dev->mdiobus->name = "lan78xx-mdiobus";
+ dev->mdiobus->parent = &dev->udev->dev;

snprintf(dev->mdiobus->id, MII_BUS_ID_SIZE, "usb-%03d:%03d",
dev->udev->bus->busnum, dev->udev->devnum);
--
2.20.1