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-rw-r--r--kernel/irq/chip.c31
-rw-r--r--kernel/irq/manage.c18
2 files changed, 40 insertions, 9 deletions
diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
index d70394f12ee..71eba24a39a 100644
--- a/kernel/irq/chip.c
+++ b/kernel/irq/chip.c
@@ -359,6 +359,23 @@ static inline void mask_ack_irq(struct irq_desc *desc, int irq)
if (desc->chip->ack)
desc->chip->ack(irq);
}
+ desc->status |= IRQ_MASKED;
+}
+
+static inline void mask_irq(struct irq_desc *desc, int irq)
+{
+ if (desc->chip->mask) {
+ desc->chip->mask(irq);
+ desc->status |= IRQ_MASKED;
+ }
+}
+
+static inline void unmask_irq(struct irq_desc *desc, int irq)
+{
+ if (desc->chip->unmask) {
+ desc->chip->unmask(irq);
+ desc->status &= ~IRQ_MASKED;
+ }
}
/*
@@ -484,10 +501,8 @@ handle_level_irq(unsigned int irq, struct irq_desc *desc)
raw_spin_lock(&desc->lock);
desc->status &= ~IRQ_INPROGRESS;
- if (unlikely(desc->status & IRQ_ONESHOT))
- desc->status |= IRQ_MASKED;
- else if (!(desc->status & IRQ_DISABLED) && desc->chip->unmask)
- desc->chip->unmask(irq);
+ if (!(desc->status & (IRQ_DISABLED | IRQ_ONESHOT)))
+ unmask_irq(desc, irq);
out_unlock:
raw_spin_unlock(&desc->lock);
}
@@ -524,8 +539,7 @@ handle_fasteoi_irq(unsigned int irq, struct irq_desc *desc)
action = desc->action;
if (unlikely(!action || (desc->status & IRQ_DISABLED))) {
desc->status |= IRQ_PENDING;
- if (desc->chip->mask)
- desc->chip->mask(irq);
+ mask_irq(desc, irq);
goto out;
}
@@ -593,7 +607,7 @@ handle_edge_irq(unsigned int irq, struct irq_desc *desc)
irqreturn_t action_ret;
if (unlikely(!action)) {
- desc->chip->mask(irq);
+ mask_irq(desc, irq);
goto out_unlock;
}
@@ -605,8 +619,7 @@ handle_edge_irq(unsigned int irq, struct irq_desc *desc)
if (unlikely((desc->status &
(IRQ_PENDING | IRQ_MASKED | IRQ_DISABLED)) ==
(IRQ_PENDING | IRQ_MASKED))) {
- desc->chip->unmask(irq);
- desc->status &= ~IRQ_MASKED;
+ unmask_irq(desc, irq);
}
desc->status &= ~IRQ_PENDING;
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index eb6078ca60c..69a3d7b9414 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -483,8 +483,26 @@ static int irq_wait_for_interrupt(struct irqaction *action)
*/
static void irq_finalize_oneshot(unsigned int irq, struct irq_desc *desc)
{
+again:
chip_bus_lock(irq, desc);
raw_spin_lock_irq(&desc->lock);
+
+ /*
+ * Implausible though it may be we need to protect us against
+ * the following scenario:
+ *
+ * The thread is faster done than the hard interrupt handler
+ * on the other CPU. If we unmask the irq line then the
+ * interrupt can come in again and masks the line, leaves due
+ * to IRQ_INPROGRESS and the irq line is masked forever.
+ */
+ if (unlikely(desc->status & IRQ_INPROGRESS)) {
+ raw_spin_unlock_irq(&desc->lock);
+ chip_bus_sync_unlock(irq, desc);
+ cpu_relax();
+ goto again;
+ }
+
if (!(desc->status & IRQ_DISABLED) && (desc->status & IRQ_MASKED)) {
desc->status &= ~IRQ_MASKED;
desc->chip->unmask(irq);