From 3c3070d713d798f7f9e7ee3614e49b47655d14d8 Mon Sep 17 00:00:00 2001 From: "Maciej W. Rozycki" Date: Tue, 3 Oct 2006 16:18:35 +0100 Subject: [PATCH] [PATCH] 2.6.18: sb1250-mac: Phylib IRQ handling fixes This patch fixes a couple of problems discovered with interrupt handling in the phylib core, namely: 1. The driver uses timer and workqueue calls, but does not include nor . 2. The driver uses schedule_work() for handling interrupts, but does not make sure any pending work scheduled thus has been completed before driver's structures get freed from memory. This is especially important as interrupts may keep arriving if the line is shared with another PHY. The solution is to ignore phy_interrupt() calls if the reported device has already been halted and calling flush_scheduled_work() from phy_stop_interrupts() (but guarded with current_is_keventd() in case the function has been called through keventd from the MAC device's close call to avoid a deadlock on the netlink lock). Signed-off-by: Maciej W. Rozycki patch-mips-2.6.18-20060920-phy-irq-16 Signed-off-by: Jeff Garzik --- drivers/net/phy/phy.c | 32 ++++++++++++++++++++++++++------ 1 file changed, 26 insertions(+), 6 deletions(-) diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c index 3af9fcf76c81..95f0419ba21e 100644 --- a/drivers/net/phy/phy.c +++ b/drivers/net/phy/phy.c @@ -7,6 +7,7 @@ * Author: Andy Fleming * * Copyright (c) 2004 Freescale Semiconductor, Inc. + * Copyright (c) 2006 Maciej W. Rozycki * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License as published by the @@ -32,6 +33,8 @@ #include #include #include +#include +#include #include #include @@ -484,6 +487,9 @@ static irqreturn_t phy_interrupt(int irq, void *phy_dat) { struct phy_device *phydev = phy_dat; + if (PHY_HALTED == phydev->state) + return IRQ_NONE; /* It can't be ours. */ + /* The MDIO bus is not allowed to be written in interrupt * context, so we need to disable the irq here. A work * queue will write the PHY to disable and clear the @@ -577,6 +583,13 @@ int phy_stop_interrupts(struct phy_device *phydev) if (err) phy_error(phydev); + /* + * Finish any pending work; we might have been scheduled + * to be called from keventd ourselves, though. + */ + if (!current_is_keventd()) + flush_scheduled_work(); + free_irq(phydev->irq, phydev); return err; @@ -603,7 +616,8 @@ static void phy_change(void *data) enable_irq(phydev->irq); /* Reenable interrupts */ - err = phy_config_interrupt(phydev, PHY_INTERRUPT_ENABLED); + if (PHY_HALTED != phydev->state) + err = phy_config_interrupt(phydev, PHY_INTERRUPT_ENABLED); if (err) goto irq_enable_err; @@ -624,18 +638,24 @@ void phy_stop(struct phy_device *phydev) if (PHY_HALTED == phydev->state) goto out_unlock; - if (phydev->irq != PHY_POLL) { - /* Clear any pending interrupts */ - phy_clear_interrupt(phydev); + phydev->state = PHY_HALTED; + if (phydev->irq != PHY_POLL) { /* Disable PHY Interrupts */ phy_config_interrupt(phydev, PHY_INTERRUPT_DISABLED); - } - phydev->state = PHY_HALTED; + /* Clear any pending interrupts */ + phy_clear_interrupt(phydev); + } out_unlock: spin_unlock(&phydev->lock); + + /* + * Cannot call flush_scheduled_work() here as desired because + * of rtnl_lock(), but PHY_HALTED shall guarantee phy_change() + * will not reenable interrupts. + */ }