On Wed, Jul 06, 2016 at 10:57:19AM +0200, Linus Walleij wrote:

quoted

+       gpiochip_irqchip_add(&wg->chip, &wcove_irqchip, 0,
+                            handle_simple_irq, IRQ_TYPE_NONE);

Reexamine the use of handle_simple_irq() here. We have two kinds of
irq hardware: those with one register for ACKing and reading the status
of an IRQ, and those with two registers for it: one where you ACK the
IRQ (so it can immediately re-trigger) and one to read the status of
whether it happened. Sometimes different handling is needed for
levek and edge IRQs even (c.f. gpio-pl061.c).

Only the hardware with just one register for both things should use
handle_simple_irq(). This seems to be the case here but I want you
to verify.

Yes, our case is handle_simple_irq(), not handle_edge_irq(), handle_level_irq() or
handle_fasteoi_irq(), etc. because there is no ACK mechanism inside the
GPIO controller's interrupt logic - all we need to do is read the status
register to get the status and write-to-clear the status register so that
a new interrupt can be triggered, i.e. there is only one register for both.

Yours,
Linus Walleij