Re: ipipe 4.19: spurious APIC interrupt when setting rt_igp to up

[Philippe Gerum <rpm@xenomai.org>]

On 7/5/19 9:38 AM, Jan Kiszka wrote:

> This addresses it on x86 for me:
> 
> diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
> index 6c279e065879..d503b875f086 100644
> --- a/kernel/irq/chip.c
> +++ b/kernel/irq/chip.c
> @@ -1099,7 +1099,8 @@ void ipipe_enable_irq(unsigned int irq)
>  		ipipe_root_only();
>  
>  		raw_spin_lock_irqsave(&desc->lock, flags);
> -		if (desc->istate & IPIPE_IRQS_NEEDS_STARTUP) {
> +		if (desc->istate & IPIPE_IRQS_NEEDS_STARTUP &&
> +		    !WARN_ON(irq_activate(desc))) {
>  			desc->istate &= ~IPIPE_IRQS_NEEDS_STARTUP;
>  			chip->irq_startup(&desc->irq_data);
>  		}
> 
> Probably upstream commit c942cee46bba (genirq: Separate activation and
> startup) makes this necessary.
> 
> Philippe, I suppose this is either not essential on arm, or external
> interrupts weren't tested yet, like I missed on x86. Fine to make this a
> noarch patch?

No issue. I've not been working on/with the I-pipe but Dovetail instead
in the past weeks, so testing of 4.19 is still very limited on my end. I
have several full-fledged real world ARM*-based application systems to
improve this, just need to find a way to squeeze this work in.

-- 
Philippe.