Re: [PATCH 1/3] gpio: pl061: lock IRQs when starting them

[Baruch Siach <baruch@tkos.co.il>]

Hi Linus,

On Tue, Nov 26, 2013 at 02:23:47PM +0100, Linus Walleij wrote:
> This uses the new API for tagging GPIO lines as in use by
> IRQs. This enforces a few semantic checks on how the underlying
> GPIO line is used.
> 
> Cc: Haojian Zhuang <haojian.zhuang@linaro.org>
> Cc: Baruch Siach <baruch@tkos.co.il>
> Cc: Deepak Sikri <deepak.sikri@st.com>
> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
> ---
>  drivers/gpio/gpio-pl061.c | 22 ++++++++++++++++++++++
>  1 file changed, 22 insertions(+)
> 
> diff --git a/drivers/gpio/gpio-pl061.c b/drivers/gpio/gpio-pl061.c
> index f22f7f3e2e53..1c37c97acc76 100644
> --- a/drivers/gpio/gpio-pl061.c
> +++ b/drivers/gpio/gpio-pl061.c
> @@ -231,11 +231,33 @@ static void pl061_irq_unmask(struct irq_data *d)
>  	spin_unlock(&chip->lock);
>  }
>  
> +static unsigned int pl061_irq_startup(struct irq_data *d)
> +{
> +	struct pl061_gpio *chip = irq_data_get_irq_chip_data(d);
> +
> +	if (gpio_lock_as_irq(&chip->gc, irqd_to_hwirq(d)))
> +		dev_err(chip->gc.dev,
> +			"unable to lock HW IRQ %lu for IRQ\n",
> +			irqd_to_hwirq(d));

What is this locking good for if locking is not enforced (i.e. error out)?

baruch

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