On 10/12/2013 12:06 AM, Jean-Christophe PLAGNIOL-VILLARD wrote: > On 13:10 Fri 11 Oct , Stephen Warren wrote: >> On 10/11/2013 02:39 AM, Linus Walleij wrote: >>> On Tue, Sep 24, 2013 at 7:51 PM, Stephen Warren <[email protected]> >>> wrote: >>>> On 09/24/2013 05:33 AM, Linus Walleij wrote: >> >>>>> diff --git a/drivers/pinctrl/pinctrl-nomadik.c >>>>> b/drivers/pinctrl/pinctrl-nomadik.c >>>>> @@ -795,6 +795,14 @@ static int nmk_gpio_to_irq(struct gpio_chip *chip, >>>>> unsigned offset) >>>>> { >>>>> struct nmk_gpio_chip *nmk_chip = >>>>> container_of(chip, struct nmk_gpio_chip, chip); >>>>> + int ret; >>>>> + >>>>> + ret = gpio_lock_as_irq(chip, offset); >>>> >>>> I don't think that gpio_to_irq() is the correct place to call the new >>>> function, for two reasons: >>>> >>>> 1) >>>> >>>> Not all paths that use interrupts call gpio_to_irq(). It's perfectly >>>> valid for a driver to receive an IRQ number, request it, and be done. >>>> The is commmon when a driver only cares about IRQ functionality and not >>>> GPIO functionality, and hence did not receive a GPIO and convert it to >>>> the IRQ. >>>> >>>> To solve this, I think irq_chip drivers should call the new gpiolib >>>> functions when the IRQ is actually requested or set up. >>>> >>>> Related, where does gpio_unlock_as_irq() get called in the Nomadik >>>> driver? It should happen when free_irq() is called. >>> >>> Yeah if we formalize the criterion that interrupts out of any GPIO >>> chips should be possible to request without first getting it from the >>> <linux/gpio.h> interface, then this holds. >>> >>> However that is not the whole story, is it? We have a gazillion >>> drivers calling irq_create_mapping() in this function, so I would >>> say that things are already a mess here. >> >> I expect things are a mess indeed:-) >> >> I believe that if a driver is only calling irq_create_mapping() inside >> gpio_to_irq(), it's a bug. I think things can operate correctly in one >> of two cases, at least with DT: >> >> 1) irq_create_mapping() is called from both gpio_to_irq() and the >> of_xlate callback for IRQs. >> >> (I don't think this method would work in a board-file-based system where >> of_xlate isn't called for IRQs...) > > this is what do the at91 driver today > >> or: >> >> 2) irq_create_mapping() is called for all IRQs when registering the IRQ >> controller/domain. >> >> To me, (2) is much simpler, and avoids the issue (1) probably has with >> only supporting direct IRQ usage (without something calling gpio_to_irq()). > > no as you can not track which gpio is an activer IRQ > as if an gpio is an active IRQ you need to forbiden gpio_directio & co
I think you're confusing two issues. The existance of an IRQ mapping is not related to whether a GPIO is used as an IRQ. In that patch that Linus sent for the nomadik GPIO driver, whether a GPIO is used as an IRQ is configured in the irq_chip startup/shutdown functions, and has no impact on, nor is impacted by, the presence/absence of IRQ mappings. -- To unsubscribe from this list: send the line "unsubscribe linux-gpio" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
