| From | Greg Kroah-Hartman <> | Subject | [PATCH 5.4 051/123] net: phy: avoid clearing PHY interrupts twice in irq handler | Date | Tue, 17 Mar 2020 11:54:38 +0100 |
| |
From: Heiner Kallweit <hkallweit1@gmail.com>
[ Upstream commit 249bc9744e165abe74ae326f43e9d70bad54c3b7 ]
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 <michael@walle.cc> Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- drivers/net/phy/phy.c | 3 ++- include/linux/phy.h | 1 + 2 files changed, 3 insertions(+), 1 deletion(-)
--- a/drivers/net/phy/phy.c +++ b/drivers/net/phy/phy.c @@ -761,7 +761,8 @@ static irqreturn_t phy_interrupt(int irq 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; --- a/include/linux/phy.h +++ b/include/linux/phy.h @@ -524,6 +524,7 @@ 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);
|