linux-kernel - Re: [PATCH 1/4] gpio: gpiolib: Allow GPIO IRQs to lazy disable

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Date:   Sat, 23 May 2020 10:42:58 +0100
From:   Marc Zyngier <maz@...nel.org>
To:     Maulik Shah <mkshah@...eaurora.org>
Cc:     bjorn.andersson@...aro.org, linus.walleij@...aro.org,
        swboyd@...omium.org, evgreen@...omium.org, mka@...omium.org,
        linux-kernel@...r.kernel.org, linux-arm-msm@...r.kernel.org,
        linux-gpio@...r.kernel.org, agross@...nel.org, tglx@...utronix.de,
        jason@...edaemon.net, dianders@...omium.org, rnayak@...eaurora.org,
        ilina@...eaurora.org, lsrao@...eaurora.org
Subject: Re: [PATCH 1/4] gpio: gpiolib: Allow GPIO IRQs to lazy disable

On 2020-05-22 14:19, Maulik Shah wrote:
> With 'commit 461c1a7d4733 ("gpiolib: override irq_enable/disable")' 
> gpiolib
> overrides irqchip's irq_enable and irq_disable callbacks. If 
> irq_disable
> callback is implemented then genirq takes unlazy path to disable irq.
> 
> Underlying irqchip may not want to implement irq_disable callback to 
> lazy
> disable irq when client drivers invokes disable_irq(). By overriding
> irq_disable callback, gpiolib ends up always unlazy disabling IRQ.
> 
> Allow gpiolib to lazy disable IRQs by overriding irq_disable callback 
> only
> if irqchip implemented irq_disable. In cases where irq_disable is not
> implemented irq_mask is overridden. Similarly override irq_enable 
> callback
> only if irqchip implemented irq_enable otherwise irq_unmask is 
> overridden.
> 
> Fixes: 461c1a7d47 (gpiolib: override irq_enable/disable)
> Signed-off-by: Maulik Shah <mkshah@...eaurora.org>
> ---
>  drivers/gpio/gpiolib.c      | 59 
> +++++++++++++++++++++++++++++----------------
>  include/linux/gpio/driver.h | 13 ++++++++++
>  2 files changed, 51 insertions(+), 21 deletions(-)
> 
> diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
> index eaa0e20..a8fdc74 100644
> --- a/drivers/gpio/gpiolib.c
> +++ b/drivers/gpio/gpiolib.c
> @@ -2465,33 +2465,38 @@ static void gpiochip_irq_relres(struct irq_data 
> *d)
>  	gpiochip_relres_irq(gc, d->hwirq);
>  }
> 
> +static void gpiochip_irq_mask(struct irq_data *d)
> +{
> +	struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
> +
> +	if (chip->irq.irq_mask)
> +		chip->irq.irq_mask(d);
> +	gpiochip_disable_irq(chip, d->hwirq);
> +}
> +
> +static void gpiochip_irq_unmask(struct irq_data *d)
> +{
> +	struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
> +
> +	gpiochip_enable_irq(chip, d->hwirq);
> +	if (chip->irq.irq_unmask)
> +		chip->irq.irq_unmask(d);
> +}
> +
>  static void gpiochip_irq_enable(struct irq_data *d)
>  {
>  	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
> 
> -	gpiochip_enable_irq(gc, d->hwirq);
> -	if (gc->irq.irq_enable)
> -		gc->irq.irq_enable(d);
> -	else
> -		gc->irq.chip->irq_unmask(d);
> +	gpiochip_enable_irq(chip, d->hwirq);

You really never compiled this, did you?

I've stopped looking at this. Please send something that you will have 
actually tested.

         M.
-- 
Jazz is not dead. It just smells funny...