From 249bc9744e165abe74ae326f43e9d70bad54c3b7 Mon Sep 17 00:00:00 2001
From: Heiner Kallweit <hkallweit1@gmail.com>
Date: Sun, 1 Mar 2020 21:36:09 +0100
Subject: [PATCH] net: phy: avoid clearing PHY interrupts twice in irq handler
Git-commit: 249bc9744e165abe74ae326f43e9d70bad54c3b7
Patch-mainline: v5.6-rc6
References: git-fixes
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>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
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);
--
2.16.4