Several irqchip drivers require the level-triggered interrupt to be acked before unmasking to avoid that a second interrupt is immediately triggered. This small patch introduces a new irqchip flags that is used to ack the IRQ line before it is unmasked.
Signed-off-by: Carlo Caione <[email protected]> --- include/linux/irq.h | 2 ++ kernel/irq/chip.c | 10 ++++++++++ kernel/irq/internals.h | 1 + kernel/irq/manage.c | 2 +- 4 files changed, 14 insertions(+), 1 deletion(-) diff --git a/include/linux/irq.h b/include/linux/irq.h index 7dc1003..2cbe8d1 100644 --- a/include/linux/irq.h +++ b/include/linux/irq.h @@ -349,6 +349,7 @@ struct irq_chip { * IRQCHIP_ONOFFLINE_ENABLED: Only call irq_on/off_line callbacks * when irq enabled * IRQCHIP_SKIP_SET_WAKE: Skip chip.irq_set_wake(), for this irq chip + * IRQCHIP_ACK_ON_UNMASK: Ack level interrupts right before unmask */ enum { IRQCHIP_SET_TYPE_MASKED = (1 << 0), @@ -357,6 +358,7 @@ enum { IRQCHIP_ONOFFLINE_ENABLED = (1 << 3), IRQCHIP_SKIP_SET_WAKE = (1 << 4), IRQCHIP_ONESHOT_SAFE = (1 << 5), + IRQCHIP_ACK_ON_UNMASK = (1 << 6), }; /* This include will go away once we isolated irq_desc usage to core code */ diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c index dc04c16..9d2d2e2 100644 --- a/kernel/irq/chip.c +++ b/kernel/irq/chip.c @@ -265,6 +265,16 @@ static inline void mask_ack_irq(struct irq_desc *desc) irq_state_set_masked(desc); } +void ack_unmask_irq(struct irq_desc *desc) +{ + if ((desc->irq_data.chip->flags & IRQCHIP_ACK_ON_UNMASK) && + (irqd_get_trigger_type(&desc->irq_data) & IRQ_TYPE_LEVEL_MASK) && + desc->irq_data.chip->irq_ack) + desc->irq_data.chip->irq_ack(&desc->irq_data); + + unmask_irq(desc); +} + void mask_irq(struct irq_desc *desc) { if (desc->irq_data.chip->irq_mask) { diff --git a/kernel/irq/internals.h b/kernel/irq/internals.h index 001fa5b..06ff850 100644 --- a/kernel/irq/internals.h +++ b/kernel/irq/internals.h @@ -73,6 +73,7 @@ extern void irq_percpu_enable(struct irq_desc *desc, unsigned int cpu); extern void irq_percpu_disable(struct irq_desc *desc, unsigned int cpu); extern void mask_irq(struct irq_desc *desc); extern void unmask_irq(struct irq_desc *desc); +extern void ack_unmask_irq(struct irq_desc *desc); extern void init_kstat_irqs(struct irq_desc *desc, int node, int nr); diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c index 481a13c..39505d8 100644 --- a/kernel/irq/manage.c +++ b/kernel/irq/manage.c @@ -718,7 +718,7 @@ again: if (!desc->threads_oneshot && !irqd_irq_disabled(&desc->irq_data) && irqd_irq_masked(&desc->irq_data)) - unmask_irq(desc); + ack_unmask_irq(desc); out_unlock: raw_spin_unlock_irq(&desc->lock); -- 1.8.5.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
