On Mon, 6 Mar 2017, Charles Keepax wrote:
> 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.
That was never meant to deal with nested shaed interrupts, so the $subject
is misleading. This is not a fix, it's a functional extension.
Aside of that, please structure the changelog in paragraphs instead of one
big lump.
1) Context
2) Problem
3) Solution
See also Documentation/process/submitting-patches.rst and please search
there for "This patch" .....
> @@ -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 {
for_each_action_of_desc() please
> + action_ret = action->thread_fn(action->irq, action->dev_id);
> + if (!noirqdebug)
> + note_interrupt(desc, action_ret);
That's wrong. See __handle_irq_event_percpu() for the correct handling of
shared interrupts vs. note_interrupt()
Thanks,
tglx
