From 4f060bf5900e8f17fb8cb8508dc08006b2a844b1 Mon Sep 17 00:00:00 2001 From: Phil Elwell Date: Tue, 15 Dec 2020 16:38:37 +0000 Subject: [PATCH] net: lan78xx: Ack pending PHY ints when resetting lan78xx_link_reset explicitly clears the MAC's view of the PHY's IRQ status. In doing so it potentially leaves the PHY with a pending interrupt that will never be acknowledged, at which point no further interrupts will be generated. Avoid the problem by acknowledging any pending PHY interrupt after clearing the MAC's status bit. See: https://github.com/raspberrypi/linux/issues/2937 Signed-off-by: Phil Elwell --- drivers/net/usb/lan78xx.c | 3 +++ 1 file changed, 3 insertions(+) --- a/drivers/net/usb/lan78xx.c +++ b/drivers/net/usb/lan78xx.c @@ -1181,6 +1181,9 @@ static int lan78xx_link_reset(struct lan if (unlikely(ret < 0)) return -EIO; + /* Acknowledge any pending PHY interrupt, lest it be the last */ + phy_read(phydev, LAN88XX_INT_STS); + mutex_lock(&phydev->lock); phy_read_status(phydev); link = phydev->link;