platform_get_resource(pdev, IORESOURCE_IRQ, ..) relies on static
allocation of IRQ resources in DT core code, this causes an issue
when using hierarchical interrupt domains using "interrupts" property
in the node as this bypassed the hierarchical setup and messed up the
irq chaining.

In preparation for removal of static setup of IRQ resource from DT core
code use platform_get_irq_optional().

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
---
v1->v2
* Check for -ENXIO in case of missing interrupt resource
---
 drivers/irqchip/irq-renesas-irqc.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/drivers/irqchip/irq-renesas-irqc.c b/drivers/irqchip/irq-renesas-irqc.c
index 07a6d8b42b63..909325f88239 100644
--- a/drivers/irqchip/irq-renesas-irqc.c
+++ b/drivers/irqchip/irq-renesas-irqc.c
@@ -126,7 +126,6 @@ static int irqc_probe(struct platform_device *pdev)
 	struct device *dev = &pdev->dev;
 	const char *name = dev_name(dev);
 	struct irqc_priv *p;
-	struct resource *irq;
 	int ret;
 	int k;
 
@@ -142,13 +141,15 @@ static int irqc_probe(struct platform_device *pdev)
 
 	/* allow any number of IRQs between 1 and IRQC_IRQ_MAX */
 	for (k = 0; k < IRQC_IRQ_MAX; k++) {
-		irq = platform_get_resource(pdev, IORESOURCE_IRQ, k);
-		if (!irq)
+		ret = platform_get_irq_optional(pdev, k);
+		if (ret == -ENXIO)
 			break;
+		if (ret < 0)
+			goto err_runtime_pm_disable;
 
 		p->irq[k].p = p;
 		p->irq[k].hw_irq = k;
-		p->irq[k].requested_irq = irq->start;
+		p->irq[k].requested_irq = ret;
 	}
 
 	p->number_of_irqs = k;
-- 
2.17.1

On Thu, Dec 16, 2021 at 7:21 PM Lad Prabhakar
<prabhakar.mahadev-lad.rj@bp.renesas.com> wrote:
> platform_get_resource(pdev, IORESOURCE_IRQ, ..) relies on static
> allocation of IRQ resources in DT core code, this causes an issue
> when using hierarchical interrupt domains using "interrupts" property
> in the node as this bypassed the hierarchical setup and messed up the
> irq chaining.
>
> In preparation for removal of static setup of IRQ resource from DT core
> code use platform_get_irq_optional().
>
> Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> ---
> v1->v2
> * Check for -ENXIO in case of missing interrupt resource

Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

The following commit has been merged into the irq/irqchip-next branch of irqchip:

Commit-ID:     befbfe6f8f744acb65c4334cc224b855d31aff1b
Gitweb:        https://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms/befbfe6f8f744acb65c4334cc224b855d31aff1b
Author:        Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
AuthorDate:    Thu, 16 Dec 2021 18:21:21 
Committer:     Marc Zyngier <maz@kernel.org>
CommitterDate: Mon, 20 Dec 2021 12:18:46 

irqchip/renesas-irqc: Use platform_get_irq_optional() to get the interrupt

platform_get_resource(pdev, IORESOURCE_IRQ, ..) relies on static
allocation of IRQ resources in DT core code, this causes an issue
when using hierarchical interrupt domains using "interrupts" property
in the node as this bypassed the hierarchical setup and messed up the
irq chaining.

In preparation for removal of static setup of IRQ resource from DT core
code use platform_get_irq_optional().

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20211216182121.5323-2-prabhakar.mahadev-lad.rj@bp.renesas.com
---
 drivers/irqchip/irq-renesas-irqc.c |  9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/drivers/irqchip/irq-renesas-irqc.c b/drivers/irqchip/irq-renesas-irqc.c
index 07a6d8b..909325f 100644
--- a/drivers/irqchip/irq-renesas-irqc.c
+++ b/drivers/irqchip/irq-renesas-irqc.c
@@ -126,7 +126,6 @@ static int irqc_probe(struct platform_device *pdev)
 	struct device *dev = &pdev->dev;
 	const char *name = dev_name(dev);
 	struct irqc_priv *p;
-	struct resource *irq;
 	int ret;
 	int k;
 
@@ -142,13 +141,15 @@ static int irqc_probe(struct platform_device *pdev)
 
 	/* allow any number of IRQs between 1 and IRQC_IRQ_MAX */
 	for (k = 0; k < IRQC_IRQ_MAX; k++) {
-		irq = platform_get_resource(pdev, IORESOURCE_IRQ, k);
-		if (!irq)
+		ret = platform_get_irq_optional(pdev, k);
+		if (ret == -ENXIO)
 			break;
+		if (ret < 0)
+			goto err_runtime_pm_disable;
 
 		p->irq[k].p = p;
 		p->irq[k].hw_irq = k;
-		p->irq[k].requested_irq = irq->start;
+		p->irq[k].requested_irq = ret;
 	}
 
 	p->number_of_irqs = k;