From 249bc9744e165abe74ae326f43e9d70bad54c3b7 Mon Sep 17 00:00:00 2001 From: Heiner Kallweit Date: Sun, 1 Mar 2020 21:36:09 +0100 Subject: net: phy: avoid clearing PHY interrupts twice in irq handler On all PHY drivers that implement did_interrupt() reading the interrupt status bits clears them. This means we may loose an interrupt that is triggered between calling did_interrupt() and phy_clear_interrupt(). As part of the fix make it a requirement that did_interrupt() clears the interrupt. The Fixes tag refers to the first commit where the patch applies cleanly. Fixes: 49644e68f472 ("net: phy: add callback for custom interrupt handler to struct phy_driver") Reported-by: Michael Walle Signed-off-by: Heiner Kallweit Signed-off-by: David S. Miller --- drivers/net/phy/phy.c | 3 ++- include/linux/phy.h | 1 + 2 files changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c index d76e038cf2cb..355bfdef48d2 100644 --- a/drivers/net/phy/phy.c +++ b/drivers/net/phy/phy.c @@ -727,7 +727,8 @@ static irqreturn_t phy_interrupt(int irq, void *phy_dat) phy_trigger_machine(phydev); } - if (phy_clear_interrupt(phydev)) + /* did_interrupt() may have cleared the interrupt already */ + if (!phydev->drv->did_interrupt && phy_clear_interrupt(phydev)) goto phy_err; return IRQ_HANDLED; diff --git a/include/linux/phy.h b/include/linux/phy.h index c570e162e05e..22f5e763e894 100644 --- a/include/linux/phy.h +++ b/include/linux/phy.h @@ -557,6 +557,7 @@ struct phy_driver { /* * Checks if the PHY generated an interrupt. * For multi-PHY devices with shared PHY interrupt pin + * Set interrupt bits have to be cleared. */ int (*did_interrupt)(struct phy_device *phydev); -- cgit v1.2.3-59-g8ed1b