[PATCH] GIC: Assign correct flow handler type in set_type callback

From: Abhijeet Dharmapurikar
Date: Thu Dec 30 2010 - 00:29:36 EST


There are some interrupts that are true edge triggered in nature. If not
marked IRQ_PENDING, when disabled, they will be lost.

Use the set_type callback to assign the correct flow type handler for
shared peripheral interrupts.

Signed-off-by: Abhijeet Dharmapurikar <adharmap@xxxxxxxxxxxxxx>
---
This came to light when a edge triggered interrupt was supposed to wakeup the
sytem. The flow handler was set to the default handle_level_irq. On the resume
path the flow handler was invoked right after the I bit was cleared but before
each individual interrupts were enabled. This made the handle_level_irq ignore
the interrupt (mask_ack it) and it was lost. handle_edge_irq does the right
thing by marking the interrupt as IRQ_PENDING and when the resume code gets to
enabling each interrupt this interrupt is resent again.

arch/arm/common/gic.c | 3 +++
1 files changed, 3 insertions(+), 0 deletions(-)

diff --git a/arch/arm/common/gic.c b/arch/arm/common/gic.c
index e6388dc..a83594a 100644
--- a/arch/arm/common/gic.c
+++ b/arch/arm/common/gic.c
@@ -136,6 +136,9 @@ static int gic_set_type(unsigned int irq, unsigned int type)

spin_unlock(&irq_controller_lock);

+ if ((type & IRQ_TYPE_EDGE_RISING) && gicirq > 31)
+ __set_irq_handler_unlocked(irq, handle_edge_irq);
+
return 0;
}

--
1.7.1
Sent by an employee of Qualcomm Innovation Center, Inc. Qualcomm Innovation
Center, Inc. is a member of Code Aurora Forum.

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