Commit 249bc974 authored Mar 01, 2020 by Heiner Kallweit Committed by David S. Miller Mar 01, 2020

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: 49644e68 ("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>

parent 52c0d4e3

drivers/net/phy/phy.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -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;

include/linux/phy.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -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);

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