On Sat, May 31, 2014 at 11:13:05AM +0200, Hans de Goede wrote: > Hi, > > On 05/28/2014 12:33 PM, Maxime Ripard wrote: > >On Wed, May 28, 2014 at 11:51:52AM +0200, Hans de Goede wrote: > >>Hi, > >> > >>On 05/28/2014 11:36 AM, Maxime Ripard wrote: > >>>On Tue, May 27, 2014 at 04:18:29PM +0200, Linus Walleij wrote: > >>>>On Mon, May 26, 2014 at 9:47 AM, Hans de Goede <hdegoede@xxxxxxxxxx> wrote: > >>>> > >>>>>With level triggered interrupt mask / unmask will get called for each > >>>>>interrupt, doing the somewhat expensive mux setting on each unmask thus is > >>>>>not a good idea. Instead move it to the set_type callback, which is typically > >>>>>done only once for each irq. > >>>>> > >>>>>Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx> > >>>> > >>>>Yes move it out of mask/unmask but no, not into set_type(). > >>>> > >>>>Can you not use the irqchip startup()/shutdown() callbacks > >>>>instead? > >>> > >>>I think we can use irq_request_resources then > >>>https://lkml.org/lkml/2014/3/12/307 > >> > >>Sounds good, I'll modify the patch to move it here before posting a v2 of > >>this series. Note v2 likely won't happen till this weekend, -ENOTIME. > >> > >>>We could even merge the gpio_to_irq code into it. > >> > >>Erm, no we need that as a separate function for the gpio_chip's to_irq > >>callback. > > > >Linus sent a patch stating otherwise a few weeks ago, and was > >suggesting moving it to irq_startup. > > > >https://lkml.org/lkml/2014/5/9/50 > > That is not going to work, that patch uses gpiochip_irqchip_add, > which in turn uses gpiochip_to_irq as to_irq handler, which > assumes that gpio offset == irq offset, which is not true for > sunxi-pinctrl. > > Specifically gpio_chio_to_irq does: > > static int gpiochip_to_irq(struct gpio_chip *chip, unsigned offset) > { > return irq_find_mapping(chip->irqdomain, offset); > } > > Where as the sunxi code does (simplified): > > static int sunxi_pinctrl_gpio_to_irq(struct gpio_chip *chip, unsigned offset) > { > struct sunxi_desc_function *desc = sunxi_pinctrl_desc_find_function_by_pin(pctl, offset, "irq"); > return irq_find_mapping(pctl->domain, desc->irqnum);\ > } Yes, I know it's not going to work, but my point was that gpio_to_irq might not be called by the drivers, and it's still valid not to do it. So we might end up with a driver requesting an interrupt that won't be muxed to it. But thinking more about it, it would be wrong to remove the .to_irq callback completely either, since drivers might need a "secondary" interrupt (like the card detect one for an MMC driver), and a lot of these use an additional gpio property to do so. So we need to keep it. Nevermind then. Maxime -- Maxime Ripard, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com
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