On Mon, 19 Feb 2024 at 17:53, Marc Zyngier <maz@xxxxxxxxxx> wrote:
>
> On Mon, 19 Feb 2024 14:47:37 +0000,
> Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx> wrote:
> >
> > Before the commit de1ff306dcf4 ("genirq/irqdomain: Remove the param
> > count restriction from select()") the irq_find_matching_fwspec() was
> > handling the DOMAIN_BUS_ANY on its own. After this commit it is a job of
> > the select() callback. However the callback of GICv3 (even though it got
> > modified to handle zero param_count) wasn't prepared to return true for
> > DOMAIN_BUS_ANY bus_token.
> >
> > This breaks probing of any of the child IRQ domains, since
> > platform_irqchip_probe() uses irq_find_matching_host(par_np,
> > DOMAIN_BUS_ANY) to check for the presence of the parent IRQ domain.
> >
> > Fixes: 151378251004 ("irqchip/gic-v3: Make gic_irq_domain_select() robust for zero parameter count")
> > Fixes: de1ff306dcf4 ("genirq/irqdomain: Remove the param count restriction from select()")
> > Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
> > ---
> > drivers/irqchip/irq-gic-v3.c | 3 ++-
> > 1 file changed, 2 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c
> > index 6fb276504bcc..e9e9643c653f 100644
> > --- a/drivers/irqchip/irq-gic-v3.c
> > +++ b/drivers/irqchip/irq-gic-v3.c
> > @@ -1696,7 +1696,8 @@ static int gic_irq_domain_select(struct irq_domain *d,
> >
> > /* Handle pure domain searches */
> > if (!fwspec->param_count)
> > - return d->bus_token == bus_token;
> > + return d->bus_token == bus_token ||
> > + bus_token == DOMAIN_BUS_ANY;
> >
> > /* If this is not DT, then we have a single domain */
> > if (!is_of_node(fwspec->fwnode))
> >
>
> I really dislike the look of this. If that's the case, any irqchip
> that has a 'select' method (such as imx-intmux) should be similarly
> hacked. And at this point, this should be handled by the core code.
>
> Can you try this instead? I don't have any HW that relies on
> behaviour, but I'd expect this to work.
>
> Thanks,
>
> M.
>
> diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c
> index aeb41655d6de..3dd1c871e091 100644
> --- a/kernel/irq/irqdomain.c
> +++ b/kernel/irq/irqdomain.c
> @@ -449,7 +449,7 @@ struct irq_domain *irq_find_matching_fwspec(struct irq_fwspec *fwspec,
> */
> mutex_lock(&irq_domain_mutex);
> list_for_each_entry(h, &irq_domain_list, link) {
> - if (h->ops->select)
> + if (h->ops->select && bus_token != DOMAIN_BUS_ANY)
> rc = h->ops->select(h, fwspec, bus_token);
> else if (h->ops->match)
> rc = h->ops->match(h, to_of_node(fwnode), bus_token);
This works. But I wonder if the following change is even better. WDYT?
diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c
index aeb41655d6de..2f0d2700709e 100644
--- a/kernel/irq/irqdomain.c
+++ b/kernel/irq/irqdomain.c
@@ -449,14 +449,17 @@ struct irq_domain
*irq_find_matching_fwspec(struct irq_fwspec *fwspec,
*/
mutex_lock(&irq_domain_mutex);
list_for_each_entry(h, &irq_domain_list, link) {
- if (h->ops->select)
+ if (fwnode != NULL &&
+ h->fwnode == fwnode &&
+ bus_token == DOMAIN_BUS_ANY)
+ rc = true;
+ else if (h->ops->select)
rc = h->ops->select(h, fwspec, bus_token);
else if (h->ops->match)
rc = h->ops->match(h, to_of_node(fwnode), bus_token);
else
rc = ((fwnode != NULL) && (h->fwnode == fwnode) &&
- ((bus_token == DOMAIN_BUS_ANY) ||
- (h->bus_token == bus_token)));
+ (h->bus_token == bus_token));
if (rc) {
found = h;
--
With best wishes
Dmitry
