From 6daf65310374d24d888201b7a6eba90b44008b7b Mon Sep 17 00:00:00 2001 From: "Maciej W. Rozycki" Date: Fri, 28 Sep 2007 22:42:15 -0700 Subject: [PATCH] PHYLIB: fix an interrupt loop potential when halting Ensure the PHY_HALTED state is not entered with the IRQ asserted as it could lead to an interrupt loop. There is a small window in phy_stop(), where the state of the PHY machine indicates it has been halted, but its interrupt output might still be unmasked. If an interrupt goes active right at this moment it will loop as the phy_interrupt() handler exits immediately with IRQ_NONE if the halted state is seen. It is unsafe to extend the phydev spinlock to cover phy_interrupt(). It is safe to swap the order of the actions though as all the competing places to unmask the interrupt output of the PHY, which are phy_change() and phy_timer() are already covered with the lock as is the sequence in question. Signed-off-by: Maciej W. Rozycki Cc: Andy Fleming Cc: Jeff Garzik Signed-off-by: Andrew Morton Signed-off-by: Jeff Garzik --- drivers/net/phy/phy.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c index 5a314edc2744..9bc11773705b 100644 --- a/drivers/net/phy/phy.c +++ b/drivers/net/phy/phy.c @@ -737,8 +737,6 @@ void phy_stop(struct phy_device *phydev) if (PHY_HALTED == phydev->state) goto out_unlock; - phydev->state = PHY_HALTED; - if (phydev->irq != PHY_POLL) { /* Disable PHY Interrupts */ phy_config_interrupt(phydev, PHY_INTERRUPT_DISABLED); @@ -747,6 +745,8 @@ void phy_stop(struct phy_device *phydev) phy_clear_interrupt(phydev); } + phydev->state = PHY_HALTED; + out_unlock: spin_unlock_bh(&phydev->lock);