Re: [PATCH] irqchip/jcore-aic: Fix missing allocation of IRQ descriptors

[John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>]

Hi Jason!

On Thu, 2023-05-11 at 07:56 +0100, Marc Zyngier wrote:
> On 2023-05-10 17:33, John Paul Adrian Glaubitz wrote:
> > The initialization function for the J-Core AIC aic_irq_of_init() is
> > currently missing the call to irq_alloc_descs() which allocates and
> > initializes all the IRQ descriptors. Add missing function call and
> > return the error code from irq_alloc_descs() in case the allocation
> > fails.
> > 
> > Fixes: 981b58f66cfc ("irqchip/jcore-aic: Add J-Core AIC driver")
> > Signed-off-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
> > ---
> >  drivers/irqchip/irq-jcore-aic.c | 7 +++++++
> >  1 file changed, 7 insertions(+)
> > 
> > diff --git a/drivers/irqchip/irq-jcore-aic.c 
> > b/drivers/irqchip/irq-jcore-aic.c
> > index 5f47d8ee4ae3..b9dcc8e78c75 100644
> > --- a/drivers/irqchip/irq-jcore-aic.c
> > +++ b/drivers/irqchip/irq-jcore-aic.c
> > @@ -68,6 +68,7 @@ static int __init aic_irq_of_init(struct device_node 
> > *node,
> >  	unsigned min_irq = JCORE_AIC2_MIN_HWIRQ;
> >  	unsigned dom_sz = JCORE_AIC_MAX_HWIRQ+1;
> >  	struct irq_domain *domain;
> > +	int ret;
> > 
> >  	pr_info("Initializing J-Core AIC\n");
> > 
> > @@ -100,6 +101,12 @@ static int __init aic_irq_of_init(struct 
> > device_node *node,
> >  	jcore_aic.irq_unmask = noop;
> >  	jcore_aic.name = "AIC";
> > 
> > +	ret = irq_alloc_descs(-1, min_irq, dom_sz - min_irq,
> > +			      of_node_to_nid(node));
> > +
> > +	if (ret < 0)
> > +		return ret;
> > +
> >  	domain = irq_domain_add_legacy(node, dom_sz - min_irq, min_irq, 
> > min_irq,
> >  				       &jcore_aic_irqdomain_ops,
> >  				       &jcore_aic);
> 
> [- Jason]
> 
> It really begs the question: how has it ever been working before?

Users already used a locally patched kernel to work around this problem.

> Is there any plan to modernise the port and get it to allocate
> irq_descs on demand, as we do on most architectures?

Yes, there are plans to modernize the port. We're first working on upstreaming
all kinds of patches that have been queuing up over the time.

Adrian

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