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:

quoted

On Wed, May 28, 2014 at 11:51:52AM +0200, Hans de Goede wrote:

quoted

Hi,

On 05/28/2014 11:36 AM, Maxime Ripard wrote:

quoted

On Tue, May 27, 2014 at 04:18:29PM +0200, Linus Walleij wrote:

quoted

On Mon, May 26, 2014 at 9:47 AM, Hans de Goede [off-list ref] wrote:

quoted

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 <redacted>

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.

quoted

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