Messages in this thread Patch in this message | | | Date | Wed, 19 Sep 2007 16:09:47 +0100 (BST) | From | "Maciej W. Rozycki" <> | 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.
Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org> --- 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.
Checked with checkpatch.pl and at the run time.
Please apply.
Maciej patch-mips-2.6.23-rc5-20070904-phy-halt-0 diff -up --recursive --new-file linux-mips-2.6.23-rc5-20070904.macro/drivers/net/phy/phy.c linux-mips-2.6.23-rc5-20070904/drivers/net/phy/phy.c --- linux-mips-2.6.23-rc5-20070904.macro/drivers/net/phy/phy.c 2007-09-04 04:55:42.000000000 +0000 +++ linux-mips-2.6.23-rc5-20070904/drivers/net/phy/phy.c 2007-09-16 17:17:20.000000000 +0000 @@ -722,8 +722,6 @@ 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); @@ -732,6 +730,8 @@ void phy_stop(struct phy_device *phydev) phy_clear_interrupt(phydev); } + phydev->state = PHY_HALTED; + out_unlock: spin_unlock(&phydev->lock); - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |