[PATCH 4/5] gic: dont disable INT in ack callback

From: adharmap
Date: Wed Jan 27 2010 - 14:33:18 EST


From: Abhijeet Dharmapurikar <adharmap@xxxxxxxxxxx>

Unless gic_ack_irq is called from __do_IRQ, interrupt should not
be disabled in the ack function. Disabling the interrupt causes
handle_edge_irq to never enable it again.

Signed-off-by: Abhijeet Dharmapurikar <adharmap@xxxxxxxxxxx>
---
arch/arm/common/gic.c | 29 +++++++++++++++++------------
1 files changed, 17 insertions(+), 12 deletions(-)

diff --git a/arch/arm/common/gic.c b/arch/arm/common/gic.c
index 709cf53..d47a1d7 100644
--- a/arch/arm/common/gic.c
+++ b/arch/arm/common/gic.c
@@ -67,25 +67,30 @@ static inline unsigned int gic_irq(unsigned int irq)

/*
* Routines to acknowledge, disable and enable interrupts
- *
- * Linux assumes that when we're done with an interrupt we need to
- * unmask it, in the same way we need to unmask an interrupt when
- * we first enable it.
- *
- * The GIC has a separate notion of "end of interrupt" to re-enable
- * an interrupt after handling, in order to support hardware
- * prioritisation.
- *
- * We can make the GIC behave in the way that Linux expects by making
- * our "acknowledge" routine disable the interrupt, then mark it as
- * complete.
*/
static void gic_ack_irq(unsigned int irq)
{
u32 mask = 1 << (irq % 32);

spin_lock(&irq_controller_lock);
+
+#ifndef CONFIG_GENERIC_HARDIRQS_NO__DO_IRQ
+
+ /*
+ * Linux assumes that when we're done with an interrupt we need to
+ * unmask it, in the same way we need to unmask an interrupt when
+ * we first enable it.
+ *
+ * The GIC has a separate notion of "end of interrupt" to re-enable
+ * an interrupt after handling, in order to support hardware
+ * prioritisation.
+ *
+ * We can make the GIC behave in the way that Linux expects by making
+ * our "acknowledge" routine disable the interrupt, then mark it as
+ * complete.
+ */
writel(mask, gic_dist_base(irq) + GIC_DIST_ENABLE_CLEAR + (gic_irq(irq) / 32) * 4);
+#endif
writel(gic_irq(irq), gic_cpu_base(irq) + GIC_CPU_EOI);
spin_unlock(&irq_controller_lock);
}
--
1.5.6.3

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