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Commit 56af0416 authored by Hans de Goede's avatar Hans de Goede Committed by Thomas Gleixner
Browse files

irqchip: sun4i: Fix irq 0 not working 



SUN4I_IRQ_VECTOR_REG containing 0 can mean one of 3 things:

1) no more irqs pending
2) irq 0 pending
3) spurious irq

So if we immediately get a reading of 0, check the irq-pending reg
to differentiate between 2 and 3. We only do this once to avoid
the extra check in the common case of 1) hapening after having
read the vector-reg once.

Signed-off-by: default avatarHans de Goede <hdegoede@redhat.com>
Acked-by: default avatarMaxime Ripard <maxime.ripard@free-electrons.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-sunxi@googlegroups.com
Link: http://lkml.kernel.org/r/1394733834-26839-3-git-send-email-hdegoede@redhat.com


Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent 328a4978

drivers/irqchip/irq-sun4i.c

+16 −2
Original line number Diff line number Diff line
@@ -140,10 +140,24 @@ static void __exception_irq_entry sun4i_handle_irq(struct pt_regs *regs) 
{

	u32 irq, hwirq;



	/*

	 * hwirq == 0 can mean one of 3 things:

	 * 1) no more irqs pending

	 * 2) irq 0 pending

	 * 3) spurious irq

	 * So if we immediately get a reading of 0, check the irq-pending reg

	 * to differentiate between 2 and 3. We only do this once to avoid

	 * the extra check in the common case of 1 hapening after having

	 * read the vector-reg once.

	 */

	hwirq = readl(sun4i_irq_base + SUN4I_IRQ_VECTOR_REG) >> 2;

	while (hwirq != 0) {

	if (hwirq == 0 &&

		  !(readl(sun4i_irq_base + SUN4I_IRQ_PENDING_REG(0)) & BIT(0)))

		return;



	do {

		irq = irq_find_mapping(sun4i_irq_domain, hwirq);

		handle_IRQ(irq, regs);

		hwirq = readl(sun4i_irq_base + SUN4I_IRQ_VECTOR_REG) >> 2;

	}

	} while (hwirq != 0);

}