Commit 4b357dae authored Jun 07, 2016 by Jon Hunter Committed by Marc Zyngier Jun 13, 2016

genirq: Look-up trigger type if not specified by caller

For some devices the IRQ trigger type for a device is read from
firmware, such as device-tree. The IRQ trigger type is typically read
when the mapping for IRQ is created, which is before the IRQ is
requested. Hence, the IRQ trigger type is programmed when mapping the
IRQ and not when requesting the IRQ.

Although this works for most cases, in order to support IRQ chips which
require runtime power management, which may not be accessible prior
to requesting the IRQ, it is desirable to look-up the IRQ trigger type
when it is requested. Therefore, if the IRQ trigger type is not
specified when __setup_irq() is called, look-up the saved IRQ trigger
type. This will allow us to defer the programming of the trigger type
from when the IRQ is mapped to when it is actually requested.

Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

parent b62b2cf5

kernel/irq/manage.c

+7 −0

Original line number	Diff line number	Diff line
		@@ -1116,6 +1116,13 @@ __setup_irq(unsigned int irq, struct irq_desc desc, struct irqaction new)

		new->irq = irq;

		/*
		* If the trigger type is not specified by the caller,
		* then use the default for this interrupt.
		*/
		if (!(new->flags & IRQF_TRIGGER_MASK))
		new->flags \|= irqd_get_trigger_type(&desc->irq_data);

		/*
		* Check whether the interrupt nests into another interrupt
		* thread.

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