From 35b5f6b1a82b5c586e0b24c711dc6ba944e88ef1 Mon Sep 17 00:00:00 2001 From: Nate Case Date: Tue, 29 Jan 2008 10:05:09 -0600 Subject: [PATCH] PHYLIB: Locking fixes for PHY I/O potentially sleeping PHY read/write functions can potentially sleep (e.g., a PHY accessed via I2C). The following changes were made to account for this: * Change spin locks to mutex locks * Add a BUG_ON() to phy_read() phy_write() to warn against calling them from an interrupt context. * Use work queue for PHY state machine handling since it can potentially sleep * Change phydev lock from spinlock to mutex Signed-off-by: Nate Case Acked-by: Andy Fleming Signed-off-by: Jeff Garzik Signed-off-by: David S. Miller --- drivers/net/phy/mdio_bus.c | 2 +- drivers/net/phy/phy.c | 68 ++++++++++++++++++++++++------------ drivers/net/phy/phy_device.c | 11 +++--- include/linux/phy.h | 5 +-- 4 files changed, 55 insertions(+), 31 deletions(-) diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c index c30196d0ad..6e9f619c49 100644 --- a/drivers/net/phy/mdio_bus.c +++ b/drivers/net/phy/mdio_bus.c @@ -49,7 +49,7 @@ int mdiobus_register(struct mii_bus *bus) int i; int err = 0; - spin_lock_init(&bus->mdio_lock); + mutex_init(&bus->mdio_lock); if (NULL == bus || NULL == bus->name || NULL == bus->read || diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c index 7c9e6e3495..12fccb1c76 100644 --- a/drivers/net/phy/phy.c +++ b/drivers/net/phy/phy.c @@ -26,7 +26,6 @@ #include #include #include -#include #include #include #include @@ -72,9 +71,11 @@ int phy_read(struct phy_device *phydev, u16 regnum) int retval; struct mii_bus *bus = phydev->bus; - spin_lock_bh(&bus->mdio_lock); + BUG_ON(in_interrupt()); + + mutex_lock(&bus->mdio_lock); retval = bus->read(bus, phydev->addr, regnum); - spin_unlock_bh(&bus->mdio_lock); + mutex_unlock(&bus->mdio_lock); return retval; } @@ -95,9 +96,11 @@ int phy_write(struct phy_device *phydev, u16 regnum, u16 val) int err; struct mii_bus *bus = phydev->bus; - spin_lock_bh(&bus->mdio_lock); + BUG_ON(in_interrupt()); + + mutex_lock(&bus->mdio_lock); err = bus->write(bus, phydev->addr, regnum, val); - spin_unlock_bh(&bus->mdio_lock); + mutex_unlock(&bus->mdio_lock); return err; } @@ -428,7 +431,7 @@ int phy_start_aneg(struct phy_device *phydev) { int err; - spin_lock_bh(&phydev->lock); + mutex_lock(&phydev->lock); if (AUTONEG_DISABLE == phydev->autoneg) phy_sanitize_settings(phydev); @@ -449,13 +452,14 @@ int phy_start_aneg(struct phy_device *phydev) } out_unlock: - spin_unlock_bh(&phydev->lock); + mutex_unlock(&phydev->lock); return err; } EXPORT_SYMBOL(phy_start_aneg); static void phy_change(struct work_struct *work); +static void phy_state_machine(struct work_struct *work); static void phy_timer(unsigned long data); /** @@ -476,6 +480,7 @@ void phy_start_machine(struct phy_device *phydev, { phydev->adjust_state = handler; + INIT_WORK(&phydev->state_queue, phy_state_machine); init_timer(&phydev->phy_timer); phydev->phy_timer.function = &phy_timer; phydev->phy_timer.data = (unsigned long) phydev; @@ -493,11 +498,12 @@ void phy_start_machine(struct phy_device *phydev, void phy_stop_machine(struct phy_device *phydev) { del_timer_sync(&phydev->phy_timer); + cancel_work_sync(&phydev->state_queue); - spin_lock_bh(&phydev->lock); + mutex_lock(&phydev->lock); if (phydev->state > PHY_UP) phydev->state = PHY_UP; - spin_unlock_bh(&phydev->lock); + mutex_unlock(&phydev->lock); phydev->adjust_state = NULL; } @@ -541,9 +547,9 @@ static void phy_force_reduction(struct phy_device *phydev) */ void phy_error(struct phy_device *phydev) { - spin_lock_bh(&phydev->lock); + mutex_lock(&phydev->lock); phydev->state = PHY_HALTED; - spin_unlock_bh(&phydev->lock); + mutex_unlock(&phydev->lock); } /** @@ -705,10 +711,10 @@ static void phy_change(struct work_struct *work) if (err) goto phy_err; - spin_lock_bh(&phydev->lock); + mutex_lock(&phydev->lock); if ((PHY_RUNNING == phydev->state) || (PHY_NOLINK == phydev->state)) phydev->state = PHY_CHANGELINK; - spin_unlock_bh(&phydev->lock); + mutex_unlock(&phydev->lock); atomic_dec(&phydev->irq_disable); enable_irq(phydev->irq); @@ -735,7 +741,7 @@ phy_err: */ void phy_stop(struct phy_device *phydev) { - spin_lock_bh(&phydev->lock); + mutex_lock(&phydev->lock); if (PHY_HALTED == phydev->state) goto out_unlock; @@ -751,7 +757,7 @@ void phy_stop(struct phy_device *phydev) phydev->state = PHY_HALTED; out_unlock: - spin_unlock_bh(&phydev->lock); + mutex_unlock(&phydev->lock); /* * Cannot call flush_scheduled_work() here as desired because @@ -773,7 +779,7 @@ out_unlock: */ void phy_start(struct phy_device *phydev) { - spin_lock_bh(&phydev->lock); + mutex_lock(&phydev->lock); switch (phydev->state) { case PHY_STARTING: @@ -787,19 +793,26 @@ void phy_start(struct phy_device *phydev) default: break; } - spin_unlock_bh(&phydev->lock); + mutex_unlock(&phydev->lock); } EXPORT_SYMBOL(phy_stop); EXPORT_SYMBOL(phy_start); -/* PHY timer which handles the state machine */ -static void phy_timer(unsigned long data) +/** + * phy_state_machine - Handle the state machine + * @work: work_struct that describes the work to be done + * + * Description: Scheduled by the state_queue workqueue each time + * phy_timer is triggered. + */ +static void phy_state_machine(struct work_struct *work) { - struct phy_device *phydev = (struct phy_device *)data; + struct phy_device *phydev = + container_of(work, struct phy_device, state_queue); int needs_aneg = 0; int err = 0; - spin_lock_bh(&phydev->lock); + mutex_lock(&phydev->lock); if (phydev->adjust_state) phydev->adjust_state(phydev->attached_dev); @@ -965,7 +978,7 @@ static void phy_timer(unsigned long data) break; } - spin_unlock_bh(&phydev->lock); + mutex_unlock(&phydev->lock); if (needs_aneg) err = phy_start_aneg(phydev); @@ -976,3 +989,14 @@ static void phy_timer(unsigned long data) mod_timer(&phydev->phy_timer, jiffies + PHY_STATE_TIME * HZ); } +/* PHY timer which schedules the state machine work */ +static void phy_timer(unsigned long data) +{ + struct phy_device *phydev = (struct phy_device *)data; + + /* + * PHY I/O operations can potentially sleep so we ensure that + * it's done from a process context + */ + schedule_work(&phydev->state_queue); +} diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c index 5b9e1751e1..f4c4fd8542 100644 --- a/drivers/net/phy/phy_device.c +++ b/drivers/net/phy/phy_device.c @@ -25,7 +25,6 @@ #include #include #include -#include #include #include #include @@ -80,7 +79,7 @@ struct phy_device* phy_device_create(struct mii_bus *bus, int addr, int phy_id) dev->state = PHY_DOWN; - spin_lock_init(&dev->lock); + mutex_init(&dev->lock); return dev; } @@ -656,7 +655,7 @@ static int phy_probe(struct device *dev) if (!(phydrv->flags & PHY_HAS_INTERRUPT)) phydev->irq = PHY_POLL; - spin_lock_bh(&phydev->lock); + mutex_lock(&phydev->lock); /* Start out supporting everything. Eventually, * a controller will attach, and may modify one @@ -670,7 +669,7 @@ static int phy_probe(struct device *dev) if (phydev->drv->probe) err = phydev->drv->probe(phydev); - spin_unlock_bh(&phydev->lock); + mutex_unlock(&phydev->lock); return err; @@ -682,9 +681,9 @@ static int phy_remove(struct device *dev) phydev = to_phy_device(dev); - spin_lock_bh(&phydev->lock); + mutex_lock(&phydev->lock); phydev->state = PHY_DOWN; - spin_unlock_bh(&phydev->lock); + mutex_unlock(&phydev->lock); if (phydev->drv->remove) phydev->drv->remove(phydev); diff --git a/include/linux/phy.h b/include/linux/phy.h index 554836edd9..5e43ae7514 100644 --- a/include/linux/phy.h +++ b/include/linux/phy.h @@ -88,7 +88,7 @@ struct mii_bus { /* A lock to ensure that only one thing can read/write * the MDIO bus at a time */ - spinlock_t mdio_lock; + struct mutex mdio_lock; struct device *dev; @@ -284,10 +284,11 @@ struct phy_device { /* Interrupt and Polling infrastructure */ struct work_struct phy_queue; + struct work_struct state_queue; struct timer_list phy_timer; atomic_t irq_disable; - spinlock_t lock; + struct mutex lock; struct net_device *attached_dev; -- 2.39.5