On Wednesday 29 October 2014 10:52:47 Linus Walleij wrote: > On Fri, Oct 24, 2014 at 3:46 PM, Arnd Bergmann <arnd@xxxxxxxx> wrote: > > On Friday 24 October 2014 14:14:43 Linus Walleij wrote: > > See the discussion I had on this. Yes, each line is connected to a > > GIC SPI interrupt by itself. I've discussed this with Marc Zyngier > > and Thomas Gleixner at the conference last week, and we concluded > > that we will need a new generic interface to get data out of the > > parent interrupt controller in a proper way. The current implementation > > just maps the GIC registers and reads them directly, which of course > > is not a proper way to do it. > > Hmmmmmm. OK shall we hold this driver until the infrastructure > issues are resolved? Y could send a first version that does not support the IRQ lines if he wants to speed up the process. > The following is a recurring pattern among GPIO controllers: > the GPIO controller can go offline (asycnhcronous) and while it > is offline a secondary logic triggers an IRQ that wakes the system > up, however the GPIO logic cannot really "see" that IRQ since > it was sleeping when it arrived. > > Thus a latent IRQ is pending in the wakeup logic. This concept > exists in drivers/pinctrl/nomadik/pinctrl-nomadik.c and I strongly > prefer to call these "latent irqs" as it's a clear unambigous > terminology. > > So is this a case of latent IRQs pending in the GIC? I think this case is different, from what I understand, the GPIO controller cannot implement gpio_chip->get() for any line that is connected to the GIC, and it has to ask the GIC instead. This seems independent of the online/offline state of the controller. Arnd -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
