Commit 45e52022 authored Mar 07, 2017 by Charles Keepax Committed by Thomas Gleixner Mar 11, 2017

genirq: Add support for nested shared IRQs



On a specific audio system an interrupt input of an audio CODEC is used as a
shared interrupt. That interrupt input is handled by a CODEC specific irq
chip driver and triggers a CPU interrupt via the CODEC irq output line.

The CODEC interrupt handler demultiplexes the CODEC interrupt inputs and
the interrupt handlers for these demultiplexed inputs run nested in the
context of the CODEC interrupt handler.

The demultiplexed interrupts use handle_nested_irq() as their interrupt
handler, which unfortunately has no support for shared interrupts. So the
above hardware cannot be supported.

Add shared interrupt support to handle_nested_irq() by iterating over the
interrupt action chain.

[ tglx: Massaged changelog ]

Signed-off-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Cc: patches@opensource.wolfsonmicro.com
Link: http://lkml.kernel.org/r/1488904098-5350-1-git-send-email-ckeepax@opensource.wolfsonmicro.com


Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

parent 434fd635

kernel/irq/chip.c

+4 −1

Original line number	Diff line number	Diff line
		@@ -348,7 +348,10 @@ void handle_nested_irq(unsigned int irq)
		irqd_set(&desc->irq_data, IRQD_IRQ_INPROGRESS);
		raw_spin_unlock_irq(&desc->lock);

		action_ret = action->thread_fn(action->irq, action->dev_id);
		action_ret = IRQ_NONE;
		for_each_action_of_desc(desc, action)
		action_ret \|= action->thread_fn(action->irq, action->dev_id);

		if (!noirqdebug)
		note_interrupt(desc, action_ret);

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