Re: [PATCH/RFC v2] gpio: rcar: Add Runtime PM handling for interrupts

[Linus Walleij <linus.walleij@xxxxxxxxxx>]

Top-quoting so everyone on the new To:-line gets the context.

I definately need an indication from an irqchip maintainer like tglx or Marc Z
before I merge this. Also, as in reply to the previous letter, coordinate
efforts with Jon Hunters similar problem space.

Yours,
Linus Walleij

On Thu, Feb 18, 2016 at 5:06 PM, Geert Uytterhoeven
<geert+renesas@xxxxxxxxx> wrote:

> The R-Car GPIO driver handles Runtime PM for requested GPIOs only.
>
> When using a GPIO purely as an interrupt source, no Runtime PM handling
> is done, and the GPIO module's clock may not be enabled.
>
> To fix this:
>   - Add .irq_request_resources() and .irq_release_resources() callbacks
>     to handle Runtime PM when an interrupt is requested,
>   - Add irq_bus_lock() and sync_unlock() callbacks to handle Runtime PM
>     when e.g. disabling/enabling an interrupt, or configuring the
>     interrupt type.
>
> Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
> ---
> This fixes ravb Ethernet on r8a7795/Salvator-X, which was "broken" by
> commit d5c3d84657db57bd ("net: phy: Avoid polling PHY with
> PHY_IGNORE_INTERRUPTS").
>
> Does it also fix the HDMI interrupt on r8a7791/Koelsch?
>
> v2:
>   - Handle Runtime PM in .irq_bus_{lock,sync_unlock}() instead of
>     .irq_{dis,en}able() and .irq_set_type(),
>   - Drop WARN() checks, they were just for testing.
>     In case of failures, please re-add
>
>         WARN(pm_runtime_suspended(&p->pdev->dev),
>                                   "%s: %s is runtime-suspended\n", __func__,
>                                   dev_name(&p->pdev->dev));
>
>     to gpio_rcar_read() and gpio_rcar_write().
> ---
>  drivers/gpio/gpio-rcar.c | 42 ++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 42 insertions(+)
>
> diff --git a/drivers/gpio/gpio-rcar.c b/drivers/gpio/gpio-rcar.c
> index cf41440aff91971e..d9ab0cd1d2059635 100644
> --- a/drivers/gpio/gpio-rcar.c
> +++ b/drivers/gpio/gpio-rcar.c
> @@ -196,6 +196,44 @@ static int gpio_rcar_irq_set_wake(struct irq_data *d, unsigned int on)
>         return 0;
>  }
>
> +static void gpio_rcar_irq_bus_lock(struct irq_data *d)
> +{
> +       struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
> +       struct gpio_rcar_priv *p = gpiochip_get_data(gc);
> +
> +       pm_runtime_get_sync(&p->pdev->dev);
> +}
> +
> +static void gpio_rcar_irq_bus_sync_unlock(struct irq_data *d)
> +{
> +       struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
> +       struct gpio_rcar_priv *p = gpiochip_get_data(gc);
> +
> +       pm_runtime_put(&p->pdev->dev);
> +}
> +
> +
> +static int gpio_rcar_irq_request_resources(struct irq_data *d)
> +{
> +       struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
> +       struct gpio_rcar_priv *p = gpiochip_get_data(gc);
> +       int error;
> +
> +       error = pm_runtime_get_sync(&p->pdev->dev);
> +       if (error < 0)
> +               return error;
> +
> +       return 0;
> +}
> +
> +static void gpio_rcar_irq_release_resources(struct irq_data *d)
> +{
> +       struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
> +       struct gpio_rcar_priv *p = gpiochip_get_data(gc);
> +
> +       pm_runtime_put(&p->pdev->dev);
> +}
> +
>  static irqreturn_t gpio_rcar_irq_handler(int irq, void *dev_id)
>  {
>         struct gpio_rcar_priv *p = dev_id;
> @@ -450,6 +488,10 @@ static int gpio_rcar_probe(struct platform_device *pdev)
>         irq_chip->irq_unmask = gpio_rcar_irq_enable;
>         irq_chip->irq_set_type = gpio_rcar_irq_set_type;
>         irq_chip->irq_set_wake = gpio_rcar_irq_set_wake;
> +       irq_chip->irq_bus_lock = gpio_rcar_irq_bus_lock;
> +       irq_chip->irq_bus_sync_unlock = gpio_rcar_irq_bus_sync_unlock;
> +       irq_chip->irq_request_resources = gpio_rcar_irq_request_resources;
> +       irq_chip->irq_release_resources = gpio_rcar_irq_release_resources;
>         irq_chip->flags = IRQCHIP_SET_TYPE_MASKED | IRQCHIP_MASK_ON_SUSPEND;
>
>         ret = gpiochip_add_data(gpio_chip, p);
> --
> 1.9.1
>
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