4.15-stable review patch. If anyone has any objections, please let me know.
------------------
From: Brad Mouring <brad.mouring@xxxxxx>
[ 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@xxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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);