Re: [PATCH RESEND] gpio: add MSIC gpio driver

[Mark Brown <broonie@opensource.wolfsonmicro.com>]

On Tue, Apr 10, 2012 at 02:18:04PM +0100, Alan Cox wrote:

> +	if (mg->trig_change_mask) {
> +		offset = __ffs(mg->trig_change_mask);
> +
> +		reg = msic_gpio_to_ireg(offset);
> +		if (reg < 0)
> +			goto out;
> +
> +		if (mg->trig_type & IRQ_TYPE_EDGE_RISING)
> +			trig |= MSIC_GPIO_TRIG_RISE;
> +		if (mg->trig_type & IRQ_TYPE_EDGE_FALLING)
> +			trig |= MSIC_GPIO_TRIG_FALL;
> +
> +		intel_msic_reg_update(reg, trig, MSIC_GPIO_INTCNT_MASK);
> +		mg->trig_change_mask = 0;
> +	}

What happens if we manage to get more than one change flagged while the
lock is held?

> +/* Firmware does all the masking and unmasking for us, no masking here. */
> +static void msic_irq_unmask(struct irq_data *data) { }

> +static void msic_irq_mask(struct irq_data *data) { }

Shouldn't these just be omitted if they don't do anything (or
alternatively, how does the firmware figure out that it needs to do the
masking and unmasking)?

> +	mg = kzalloc(sizeof(*mg), GFP_KERNEL);
> +	if (!mg)
> +		return -ENOMEM;

devm_kzalloc()