From 1e93937b0ba6f7b685f4128b99cf1ecdcd381ffd Mon Sep 17 00:00:00 2001 From: Phil Elwell Date: Tue, 15 Dec 2020 16:38:37 +0000 Subject: [PATCH 317/552] 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(+) diff --git a/drivers/net/usb/lan78xx.c b/drivers/net/usb/lan78xx.c index 4ac3e160389d..44ee7f83cb1b 100644 --- a/drivers/net/usb/lan78xx.c +++ b/drivers/net/usb/lan78xx.c @@ -1176,6 +1176,9 @@ static int lan78xx_link_reset(struct lan78xx_net *dev) 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; -- 2.33.0