Re: [PATCH] gpio: em: lock IRQs when starting them

[Simon Horman <horms@verge.net.au>]

On Wed, Nov 20, 2013 at 10:39:04AM +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.
> 
> Also assign the gpio_chip.dev pointer to be used for error
> messages.

Hi,

I have tested this patch on top of next-20131121 using
the emev2 based kzm9d board using its defconfig.
Unfortunately it seems to cause the following problem:

smsc911x smsc911x eth0: ISR failed signaling test (IRQ 201)

This seems to render the NIC unusable.

> Cc: Magnus Damm <damm@opensource.se>
> Cc: Ian Molton <ian.molton@codethink.co.uk>
> Cc: Simon Horman <horms+renesas@verge.net.au>
> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
> ---
>  drivers/gpio/gpio-em.c | 22 ++++++++++++++++++++++
>  1 file changed, 22 insertions(+)
> 
> diff --git a/drivers/gpio/gpio-em.c b/drivers/gpio/gpio-em.c
> index ec190361bf2e..bbf242312bda 100644
> --- a/drivers/gpio/gpio-em.c
> +++ b/drivers/gpio/gpio-em.c
> @@ -99,6 +99,25 @@ static void em_gio_irq_enable(struct irq_data *d)
>  	em_gio_write(p, GIO_IEN, BIT(irqd_to_hwirq(d)));
>  }
>  
> +static unsigned int em_gio_irq_startup(struct irq_data *d)
> +{
> +	struct em_gio_priv *p = irq_data_get_irq_chip_data(d);
> +
> +	if (gpio_lock_as_irq(&p->gpio_chip, irqd_to_hwirq(d)))
> +		dev_err(p->gpio_chip.dev,
> +			"unable to lock HW IRQ %lu for IRQ\n",
> +			irqd_to_hwirq(d));
> +	return 0;
> +}
> +
> +static void em_gio_irq_shutdown(struct irq_data *d)
> +{
> +	struct em_gio_priv *p = irq_data_get_irq_chip_data(d);
> +
> +	gpio_unlock_as_irq(&p->gpio_chip, irqd_to_hwirq(d));
> +}
> +
> +
>  #define GIO_ASYNC(x) (x + 8)
>  
>  static unsigned char em_gio_sense_table[IRQ_TYPE_SENSE_MASK + 1] = {
> @@ -328,6 +347,7 @@ static int em_gio_probe(struct platform_device *pdev)
>  	gpio_chip->request = em_gio_request;
>  	gpio_chip->free = em_gio_free;
>  	gpio_chip->label = name;
> +	gpio_chip->dev = &pdev->dev;
>  	gpio_chip->owner = THIS_MODULE;
>  	gpio_chip->base = pdata->gpio_base;
>  	gpio_chip->ngpio = pdata->number_of_pins;
> @@ -339,6 +359,8 @@ static int em_gio_probe(struct platform_device *pdev)
>  	irq_chip->irq_enable = em_gio_irq_enable;
>  	irq_chip->irq_disable = em_gio_irq_disable;
>  	irq_chip->irq_set_type = em_gio_irq_set_type;
> +	irq_chip->irq_startup = em_gio_irq_startup;
> +	irq_chip->irq_shutdown = em_gio_irq_shutdown;
>  	irq_chip->flags	= IRQCHIP_SKIP_SET_WAKE;
>  
>  	p->irq_domain = irq_domain_add_simple(pdev->dev.of_node,
> -- 
> 1.8.3.1
>