[PATCH] irqchip: omap-intc: fix legacy DMA regression

[Aaro Koskinen]

On Tue, Jan 06, 2015 at 10:51:33AM -0600, Felipe Balbi wrote:
> commit 55601c9f2467 (arm: omap: intc: switch over
> to linear irq domain) introduced a regression with
> SDMA legacy driver because that driver strictly depends
> on INTC's IRQs starting at NR_IRQs. Aparently
> irq_domain_add_linear() won't guarantee that, since we see
> a 7 IRQs difference when booting with and without the
> commit cited above.
> 
> Until arch/arm/plat-omap/dma.c is properly fixed, we
> must maintain OMAP2/3 using irq_domain_add_legacy().
> 
> A FIXME note was added so people know to delete that
> code once that legacy DMA driver is fixed up.
> 
> Fixes: 55601c9f2467 (arm: omap: intc: switch over to linear irq domain)
> Signed-off-by: Felipe Balbi <balbi at ti.com>

I tested this on N950 with 3.19-rc3, and /proc/interrupts looks sane
and also the "In-band Error" is gone.

Tested-by: Aaro Koskinen <aaro.koskinen at iki.fi>

BTW, I guess people still using 3.18.x will get the wrong IRQ for DMA,
so maybe you should consider adding also Cc: stable...

A.

> ---
>  drivers/irqchip/irq-omap-intc.c | 26 +++++++++++++++++++++-----
>  1 file changed, 21 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/irqchip/irq-omap-intc.c b/drivers/irqchip/irq-omap-intc.c
> index 3c970259c0eb..6ef88f56cf8d 100644
> --- a/drivers/irqchip/irq-omap-intc.c
> +++ b/drivers/irqchip/irq-omap-intc.c
> @@ -263,7 +263,7 @@ static int __init omap_init_irq_of(struct device_node *node)
>  	return ret;
>  }
>  
> -static int __init omap_init_irq_legacy(u32 base)
> +static int __init omap_init_irq_legacy(u32 base, struct device_node *node)
>  {
>  	int j, irq_base;
>  
> @@ -277,7 +277,7 @@ static int __init omap_init_irq_legacy(u32 base)
>  		irq_base = 0;
>  	}
>  
> -	domain = irq_domain_add_legacy(NULL, omap_nr_irqs, irq_base, 0,
> +	domain = irq_domain_add_legacy(node, omap_nr_irqs, irq_base, 0,
>  			&irq_domain_simple_ops, NULL);
>  
>  	omap_irq_soft_reset();
> @@ -301,10 +301,26 @@ static int __init omap_init_irq(u32 base, struct device_node *node)
>  {
>  	int ret;
>  
> -	if (node)
> +	/*
> +	 * FIXME legacy OMAP DMA driver sitting under arch/arm/plat-omap/dma.c
> +	 * depends is still not ready for linear IRQ domains; because of that
> +	 * we need to temporarily "blacklist" OMAP2 and OMAP3 devices from using
> +	 * linear IRQ Domain until that driver is finally fixed.
> +	 */
> +	if (of_device_is_compatible(node, "ti,omap2-intc") ||
> +			of_device_is_compatible(node, "ti,omap3-intc")) {
> +		struct resource res;
> +
> +		if (of_address_to_resource(node, 0, &res))
> +			return -ENOMEM;
> +
> +		base = res.start;
> +		ret = omap_init_irq_legacy(base, node);
> +	} else if (node) {
>  		ret = omap_init_irq_of(node);
> -	else
> -		ret = omap_init_irq_legacy(base);
> +	} else {
> +		ret = omap_init_irq_legacy(base, NULL);
> +	}
>  
>  	if (ret == 0)
>  		omap_irq_enable_protection();
> -- 
> 2.2.0
>