Re: [PATCH] mfd: Support dynamic allocation of IRQ range for wm831x

[Sascha Hauer]

Hi Mark,

On Wed, Jun 01, 2011 at 09:39:32PM +0100, Mark Brown wrote:
> Use irq_allocate_desc() to get the IRQ range, which turns into a noop on
> non-sparse systems. Since all existing users are non-sparse there should
> be no compatibility issues.
> 
> Signed-off-by: Mark Brown <broonie@xxxxxxxxxxxxxxxxxxxxxxxxxxx>
> ---
>  drivers/mfd/wm831x-irq.c |   15 ++++++++++++---
>  1 files changed, 12 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/mfd/wm831x-irq.c b/drivers/mfd/wm831x-irq.c
> index b23d8d5..a25a7d5 100644
> --- a/drivers/mfd/wm831x-irq.c
> +++ b/drivers/mfd/wm831x-irq.c
> @@ -527,9 +527,18 @@ int wm831x_irq_init(struct wm831x *wm831x, int irq)
>  				 0xffff);
>  	}
>  
> -	if (!pdata || !pdata->irq_base) {
> -		dev_err(wm831x->dev,
> -			"No interrupt base specified, no interrupts\n");
> +	/* Try to dynamically allocate IRQs if no base is specified */
> +	if (!pdata || !pdata->irq_base)
> +		wm831x->irq_base = -1;
> +	else
> +		wm831x->irq_base = pdata->irq_base;
> +
> +	wm831x->irq_base = irq_alloc_descs(wm831x->irq_base, 0,
> +					   WM831X_NUM_IRQS, 0);
> +	if (wm831x->irq_base < 0) {
> +		dev_warn(wm831x->dev, "Failed to allocate IRQs: %d\n",
> +			 wm831x->irq_base);
> +		wm831x->irq_base = 0;
>  		return 0;
>  	}

The lines you remove made sure that the rest of this function is
executed with valid pdata. At least on v3.0-rc1 pdata is used later
without validity checks. So unless there are some patches in -next
that I'm missing you need to update your patch.

Sascha

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