Re: [PATCH] genirq/generic-chip: Set IRQ_DOMAIN_FLAG_DESTROY_GC in irq_domain_alloc_generic_chips()

[Qingshuang Fu]

在 2026/9/4 14:26, Thomas Gleixner 写道:
> On Fri, Sep 04 2026 at 00:37, Herve Codina wrote:
> > On Wed,  2 Sep 2026 14:59:39 +0800
> > Qingshuang Fu <fuqingshuang@xxxxxxxxxx> wrote:
> > > diff --git a/kernel/irq/generic-chip.c b/kernel/irq/generic-chip.c
> > > index 2c8bc6ce082e..13b634053a3e 100644
> > > --- a/kernel/irq/generic-chip.c
> > > +++ b/kernel/irq/generic-chip.c
> > > @@ -308,6 +308,7 @@ int irq_domain_alloc_generic_chips(struct irq_domain *d,
> > >   	dgc->gc_flags = info->gc_flags;
> > >   	dgc->exit = info->exit;
> > >   	d->gc = dgc;
> > > +	d->flags |= IRQ_DOMAIN_FLAG_DESTROY_GC;
> > >   
> > >   	/* Calc pointer to the first generic chip */
> > >   	tmp += dgc_sz;
> > The flag has been intended to be use with irq_domain_instantiate() which can call
> > irq_domain_alloc_generic_chips() internally. Callers of irq_domain_instantiate()
> > call only irq_remove_domain().
> >
> > Indeed calling only irq_domain_instantiate() and calling both
> > irq_domain_remove_generic_chips() followed by irq_remove_domain() is, in that case,
> > not consistent too.
> >
> > IHMO, if the flag IRQ_DOMAIN_FLAG_DESTROY_GC need to be automatically set
> > somewhere, it could be in irq_domain_instantiate().
>
> Yes, in the 'if (info->dgc_info)' branch.

Hi,

Thank you very much for your valuable suggestion.

I have posted the v2 patch here:
https://lore.kernel.org/all/20260904070943.934476-1-fuqingshuang@xxxxxxxxxx/

In v2, IRQ_DOMAIN_FLAG_DESTROY_GC is now set inside the info->dgc_info
branch within __irq_domain_instantiate(), right after 
irq_domain_alloc_generic_chips()
succeeds.

Now only domains created via irq_domain_instantiate() with dgc_info get
IRQ_DOMAIN_FLAG_DESTROY_GC automatically. Explicit callers of
irq_domain_alloc_generic_chips() remain untouched and are still responsible
for cleaning‑up generic chips manually.

Regards,
Qingshuang Fu