Re: [PATCH v3 3/5] irqchip/mips-gic: Enable interrupt when moving affinity across clusters

[Thomas Bogendoerfer <tsbogend@alpha.franken.de>]

On Mon, Sep 07, 2026 at 02:46:37PM +0200, Benoît Monin wrote:
> When an interrupt's affinity is moved to a CPU in another cluster,
> gic_set_affinity() updates the routing (GIC_SH_MAP_VP) and trigger type
> in the destination cluster, but never touched the interrupt's mask state.
> 
> The interrupt mask is per-cluster. After such a move the interrupt was
> left disabled in the destination cluster, so it never fires despite
> being correctly routed to its new VP.
> 
> Handle the mask explicitly on a cross-cluster affinity change: in the
> old cluster, write GIC_SH_RMASK to disable the interrupt while clearing
> the route so it is no longer delivered. And in the new cluster, set the
> mask to enable the interrupt along with reconfiguring the trigger type.
> 
> Fixes: 322a90638768 ("irqchip/mips-gic: Multi-cluster support")
> Signed-off-by: Benoît Monin <benoit.monin@bootlin.com>
> ---
>  drivers/irqchip/irq-mips-gic.c | 16 +++++++++++++---
>  1 file changed, 13 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/irqchip/irq-mips-gic.c b/drivers/irqchip/irq-mips-gic.c
> index f2ae60d39d66..4b76a65f12c9 100644
> --- a/drivers/irqchip/irq-mips-gic.c
> +++ b/drivers/irqchip/irq-mips-gic.c
> @@ -390,14 +390,17 @@ static int gic_set_affinity(struct irq_data *d, const struct cpumask *cpumask,
>  
>  	/*
>  	 * If we're moving affinity between clusters, stop routing the
> -	 * interrupt to any VP(E) in the old cluster.
> +	 * interrupt to any VP(E) in the old cluster and disable
> +	 * the interrupt in that cluster.
>  	 */
>  	if (cl != old_cl) {
>  		if (gic_irq_lock_cluster(d)) {
>  			write_gic_redir_map_vp(irq, 0);
> +			write_gic_redir_rmask(irq);
>  			mips_cm_unlock_other();
>  		} else {
>  			write_gic_map_vp(irq, 0);
> +			write_gic_rmask(irq);
>  		}
>  	}
>  
> @@ -409,10 +412,17 @@ static int gic_set_affinity(struct irq_data *d, const struct cpumask *cpumask,
>  
>  	/*
>  	 * If we're moving affinity between clusters, configure the interrupt
> -	 * trigger type in the new cluster.
> +	 * trigger type and enable the interrupt in the new cluster.
>  	 */
> -	if (cl != old_cl)
> +	if (cl != old_cl) {
>  		gic_set_type_locked(d, irqd_get_trigger_type(d));
> +		if (gic_irq_lock_cluster(d)) {
> +			write_gic_redir_smask(irq);
> +			mips_cm_unlock_other();
> +		} else {
> +			write_gic_smask(irq);
> +		}
> +	}

shouldn't this be done depending on the mask state in the old cluster ?

Thomas.

-- 
Crap can work. Given enough thrust pigs will fly, but it's not necessarily a
good idea.                                                [ RFC1925, 2.3 ]