On Mon, 13 Mar 2017, Tony Lindgren wrote:
> Shared interrupts can be registered with handle_nested_irq(), but
> currently only one of the registered handlers gets called.
>
> The use of shared interrupts with handle_nested_irq() is probably rare,
> but at least a case of a shared VBUS interrupt between USB PHY and
> battery charger drivers for a PMIC makes sense.
>
> Typically for_each_action_of_desc() gets called via handle_irq_event()
> at _handle_irq_event_percpu(), but handle_nested_irq() is different
> because of it's dummy irq_nested_primary_handler().
>
> Let's fix the issue by calling the handler for all the entries in
> the action list.
>
> Fixes: 399b5da29b9f ("genirq: Support nested threaded irq handling")
It's not a fix, it's an extension. The nested facility was not meant to
handle shared interrupts in the first place. I really hope that hardware
folks finally understand that irq sharing is crap and broken...
> Signed-off-by: Tony Lindgren <[email protected]>
> ---
> kernel/irq/chip.c | 8 +++++---
> 1 file changed, 5 insertions(+), 3 deletions(-)
>
> diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
> --- a/kernel/irq/chip.c
> +++ b/kernel/irq/chip.c
> @@ -348,9 +348,11 @@ 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);
> + for_each_action_of_desc(desc, action) {
> + action_ret = action->thread_fn(action->irq, action->dev_id);
> + if (!noirqdebug)
> + note_interrupt(desc, action_ret);
This is wrong. See how __handle_irq_event_percpu() does this. But no need
to resend. See:
http://lkml.kernel.org/r/1488904098-5350-1-git-send-email-ckee...@opensource.wolfsonmicro.com
Thanks,
tglx
