4.15-stable review patch. If anyone has any objections, please let me know.
------------------
From: Brad Mouring brad.mouring@ni.com
[ Upstream commit a2c054a896b8ac794ddcfc7c92e2dc7ec4ed4ed5 ]
In 664fcf123a30e (net: phy: Threaded interrupts allow some simplification) the phy_interrupt system was changed to use a traditional threaded interrupt scheme instead of a workqueue approach.
With this change, the phy status check moved into phy_change, which did not report back to the caller whether or not the interrupt was handled. This means that, in the case of a shared phy interrupt, only the first phydev's interrupt registers are checked (since phy_interrupt() would always return IRQ_HANDLED). This leads to interrupt storms when it is a secondary device that's actually the interrupt source.
Signed-off-by: Brad Mouring brad.mouring@ni.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/net/phy/phy.c | 173 ++++++++++++++++++++++++-------------------------- include/linux/phy.h | 1 2 files changed, 86 insertions(+), 88 deletions(-)
--- a/drivers/net/phy/phy.c +++ b/drivers/net/phy/phy.c @@ -615,6 +615,91 @@ static void phy_error(struct phy_device }
/** + * phy_disable_interrupts - Disable the PHY interrupts from the PHY side + * @phydev: target phy_device struct + */ +static int phy_disable_interrupts(struct phy_device *phydev) +{ + int err; + + /* Disable PHY interrupts */ + err = phy_config_interrupt(phydev, PHY_INTERRUPT_DISABLED); + if (err) + goto phy_err; + + /* Clear the interrupt */ + err = phy_clear_interrupt(phydev); + if (err) + goto phy_err; + + return 0; + +phy_err: + phy_error(phydev); + + return err; +} + +/** + * phy_change - Called by the phy_interrupt to handle PHY changes + * @phydev: phy_device struct that interrupted + */ +static irqreturn_t phy_change(struct phy_device *phydev) +{ + if (phy_interrupt_is_valid(phydev)) { + if (phydev->drv->did_interrupt && + !phydev->drv->did_interrupt(phydev)) + goto ignore; + + if (phy_disable_interrupts(phydev)) + goto phy_err; + } + + mutex_lock(&phydev->lock); + if ((PHY_RUNNING == phydev->state) || (PHY_NOLINK == phydev->state)) + phydev->state = PHY_CHANGELINK; + mutex_unlock(&phydev->lock); + + if (phy_interrupt_is_valid(phydev)) { + atomic_dec(&phydev->irq_disable); + enable_irq(phydev->irq); + + /* Reenable interrupts */ + if (PHY_HALTED != phydev->state && + phy_config_interrupt(phydev, PHY_INTERRUPT_ENABLED)) + goto irq_enable_err; + } + + /* reschedule state queue work to run as soon as possible */ + phy_trigger_machine(phydev, true); + return IRQ_HANDLED; + +ignore: + atomic_dec(&phydev->irq_disable); + enable_irq(phydev->irq); + return IRQ_NONE; + +irq_enable_err: + disable_irq(phydev->irq); + atomic_inc(&phydev->irq_disable); +phy_err: + phy_error(phydev); + return IRQ_NONE; +} + +/** + * phy_change_work - Scheduled by the phy_mac_interrupt to handle PHY changes + * @work: work_struct that describes the work to be done + */ +void phy_change_work(struct work_struct *work) +{ + struct phy_device *phydev = + container_of(work, struct phy_device, phy_queue); + + phy_change(phydev); +} + +/** * phy_interrupt - PHY interrupt handler * @irq: interrupt line * @phy_dat: phy_device pointer @@ -632,9 +717,7 @@ static irqreturn_t phy_interrupt(int irq disable_irq_nosync(irq); atomic_inc(&phydev->irq_disable);
- phy_change(phydev); - - return IRQ_HANDLED; + return phy_change(phydev); }
/** @@ -652,32 +735,6 @@ static int phy_enable_interrupts(struct }
/** - * phy_disable_interrupts - Disable the PHY interrupts from the PHY side - * @phydev: target phy_device struct - */ -static int phy_disable_interrupts(struct phy_device *phydev) -{ - int err; - - /* Disable PHY interrupts */ - err = phy_config_interrupt(phydev, PHY_INTERRUPT_DISABLED); - if (err) - goto phy_err; - - /* Clear the interrupt */ - err = phy_clear_interrupt(phydev); - if (err) - goto phy_err; - - return 0; - -phy_err: - phy_error(phydev); - - return err; -} - -/** * phy_start_interrupts - request and enable interrupts for a PHY device * @phydev: target phy_device struct * @@ -728,64 +785,6 @@ int phy_stop_interrupts(struct phy_devic EXPORT_SYMBOL(phy_stop_interrupts);
/** - * phy_change - Called by the phy_interrupt to handle PHY changes - * @phydev: phy_device struct that interrupted - */ -void phy_change(struct phy_device *phydev) -{ - if (phy_interrupt_is_valid(phydev)) { - if (phydev->drv->did_interrupt && - !phydev->drv->did_interrupt(phydev)) - goto ignore; - - if (phy_disable_interrupts(phydev)) - goto phy_err; - } - - mutex_lock(&phydev->lock); - if ((PHY_RUNNING == phydev->state) || (PHY_NOLINK == phydev->state)) - phydev->state = PHY_CHANGELINK; - mutex_unlock(&phydev->lock); - - if (phy_interrupt_is_valid(phydev)) { - atomic_dec(&phydev->irq_disable); - enable_irq(phydev->irq); - - /* Reenable interrupts */ - if (PHY_HALTED != phydev->state && - phy_config_interrupt(phydev, PHY_INTERRUPT_ENABLED)) - goto irq_enable_err; - } - - /* reschedule state queue work to run as soon as possible */ - phy_trigger_machine(phydev, true); - return; - -ignore: - atomic_dec(&phydev->irq_disable); - enable_irq(phydev->irq); - return; - -irq_enable_err: - disable_irq(phydev->irq); - atomic_inc(&phydev->irq_disable); -phy_err: - phy_error(phydev); -} - -/** - * phy_change_work - Scheduled by the phy_mac_interrupt to handle PHY changes - * @work: work_struct that describes the work to be done - */ -void phy_change_work(struct work_struct *work) -{ - struct phy_device *phydev = - container_of(work, struct phy_device, phy_queue); - - phy_change(phydev); -} - -/** * phy_stop - Bring down the PHY link, and stop checking the status * @phydev: target phy_device struct */ --- a/include/linux/phy.h +++ b/include/linux/phy.h @@ -897,7 +897,6 @@ int phy_driver_register(struct phy_drive int phy_drivers_register(struct phy_driver *new_driver, int n, struct module *owner); void phy_state_machine(struct work_struct *work); -void phy_change(struct phy_device *phydev); void phy_change_work(struct work_struct *work); void phy_mac_interrupt(struct phy_device *phydev, int new_link); void phy_start_machine(struct phy_device *phydev);