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

[Tony Lindgren]

* Aaro Koskinen <aaro.koskinen at iki.fi> [150106 09:51]:
> 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...

Yeah this one should be cc stable. Fixes the error for me too:

Tested-by: Tony Lindgren <tony at atomide.com>

> > ---
> >  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
> >