[PATCH v2 4/4] irqchip: sun4i: Use handle_fasteoi_late_irq for the ENMI (irq 0)

[Thomas Gleixner]

On Thu, 13 Mar 2014, Maxime Ripard wrote:

> On Wed, Mar 12, 2014 at 06:17:07PM +0100, Hans de Goede wrote:
> > The ENMI needs to have the ack done *after* clearing the interrupt source,
> > otherwise we will get a spurious interrupt for each real interrupt. Switch
> > to the new handle_fasteoi_late_irq handler which gives us the desired behavior.
> > 
> > Signed-off-by: Hans de Goede <hdegoede at redhat.com>
> > ---
> >  drivers/irqchip/irq-sun4i.c | 11 +++++++++--
> >  1 file changed, 9 insertions(+), 2 deletions(-)
> > 
> > diff --git a/drivers/irqchip/irq-sun4i.c b/drivers/irqchip/irq-sun4i.c
> > index 8a2fbee..4b1c874 100644
> > --- a/drivers/irqchip/irq-sun4i.c
> > +++ b/drivers/irqchip/irq-sun4i.c
> > @@ -77,15 +77,22 @@ static void sun4i_irq_unmask(struct irq_data *irqd)
> >  static struct irq_chip sun4i_irq_chip = {
> >  	.name		= "sun4i_irq",
> >  	.irq_ack	= sun4i_irq_ack,
> > +	.irq_eoi	= sun4i_irq_ack, /* For the ENMI */
> 
> Hmmm, I wonder if that actually does something.
> 
> There's been a patch floating around that I was sure was merged, but
> apparently wasn't that remove sun4i_irq_ack, because the register we
> were writing to are in read only, and it wasn't doing anything.

Well, it looks like it does something otherwise Hans would not see any
improvement of the situation.