[PATCH] genirq: Fix handling of nested shared IRQs

From: Charles Keepax
Date: Mon Mar 06 2017 - 11:08:00 EST


When an IRQ is nested the nested handler is called directly from within the
threaded handler of the parent IRQ, however, the code in handle_nested_irq
only calls a single handler. This means when a shared IRQ is nested only
the first of the shared IRQ handlers will be run. This patch adds a loop
to move through and process all the handlers associated with the IRQ in
handle_nested_irq.

Signed-off-by: Charles Keepax <ckeepax@xxxxxxxxxxxxxxxxxxxxxxxxxxx>
---
kernel/irq/chip.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
index be3c34e..c6c7f11 100644
--- a/kernel/irq/chip.c
+++ b/kernel/irq/chip.c
@@ -348,9 +348,12 @@ 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);
- if (!noirqdebug)
- note_interrupt(desc, action_ret);
+ do {
+ action_ret = action->thread_fn(action->irq, action->dev_id);
+ if (!noirqdebug)
+ note_interrupt(desc, action_ret);
+ action = action->next;
+ } while (action);

raw_spin_lock_irq(&desc->lock);
irqd_clear(&desc->irq_data, IRQD_IRQ_INPROGRESS);
--
2.1.4