Commit-ID: 56af0416b00f6edc7845a7b3f2ef179e385c8e15
Gitweb: http://git.kernel.org/tip/56af0416b00f6edc7845a7b3f2ef179e385c8e15
Author: Hans de Goede <hdegoede@xxxxxxxxxx>
AuthorDate: Thu, 13 Mar 2014 19:03:52 +0100
Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitDate: Fri, 14 Mar 2014 13:43:33 +0100
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: Hans de Goede <hdegoede@xxxxxxxxxx>
Acked-by: Maxime Ripard <maxime.ripard@xxxxxxxxxxxxxxxxxx>
Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
Cc: linux-sunxi@xxxxxxxxxxxxxxxx
Link: http://lkml.kernel.org/r/1394733834-26839-3-git-send-email-hdegoede@xxxxxxxxxx
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
---
drivers/irqchip/irq-sun4i.c | 18 ++++++++++++++++--
1 file changed, 16 insertions(+), 2 deletions(-)
diff --git a/drivers/irqchip/irq-sun4i.c b/drivers/irqchip/irq-sun4i.c
index 1599955..7ae85ec 100644
--- a/drivers/irqchip/irq-sun4i.c
+++ b/drivers/irqchip/irq-sun4i.c
@@ -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);
}
--
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