FAILED: patch "[PATCH] pinctrl: stm32: fix optional IRQ support to gpios" failed to apply to 5.15-stable tree

[<gregkh@xxxxxxxxxxxxxxxxxxx>]

The patch below does not apply to the 5.15-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@xxxxxxxxxxxxxxx>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

>From a1d4ef1adf8bbd302067534ead671a94759687ed Mon Sep 17 00:00:00 2001
From: Fabien Dessenne <fabien.dessenne@xxxxxxxxxxx>
Date: Mon, 27 Jun 2022 16:23:50 +0200
Subject: [PATCH] pinctrl: stm32: fix optional IRQ support to gpios

To act as an interrupt controller, a gpio bank relies on the
"interrupt-parent" of the pin controller.
When this optional "interrupt-parent" misses, do not create any IRQ domain.

This fixes a "NULL pointer in stm32_gpio_domain_alloc()" kernel crash when
the interrupt-parent = <exti> property is not declared in the Device Tree.

Fixes: 0eb9f683336d ("pinctrl: Add IRQ support to STM32 gpios")
Signed-off-by: Fabien Dessenne <fabien.dessenne@xxxxxxxxxxx>
Link: https://lore.kernel.org/r/20220627142350.742973-1-fabien.dessenne@xxxxxxxxxxx
Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx>

diff --git a/drivers/pinctrl/stm32/pinctrl-stm32.c b/drivers/pinctrl/stm32/pinctrl-stm32.c
index 57a33fb0f2d7..14bcca73238a 100644
--- a/drivers/pinctrl/stm32/pinctrl-stm32.c
+++ b/drivers/pinctrl/stm32/pinctrl-stm32.c
@@ -1338,16 +1338,18 @@ static int stm32_gpiolib_register_bank(struct stm32_pinctrl *pctl, struct fwnode
 	bank->secure_control = pctl->match_data->secure_control;
 	spin_lock_init(&bank->lock);
 
-	/* create irq hierarchical domain */
-	bank->fwnode = fwnode;
+	if (pctl->domain) {
+		/* create irq hierarchical domain */
+		bank->fwnode = fwnode;
 
-	bank->domain = irq_domain_create_hierarchy(pctl->domain, 0,
-					STM32_GPIO_IRQ_LINE, bank->fwnode,
-					&stm32_gpio_domain_ops, bank);
+		bank->domain = irq_domain_create_hierarchy(pctl->domain, 0, STM32_GPIO_IRQ_LINE,
+							   bank->fwnode, &stm32_gpio_domain_ops,
+							   bank);
 
-	if (!bank->domain) {
-		err = -ENODEV;
-		goto err_clk;
+		if (!bank->domain) {
+			err = -ENODEV;
+			goto err_clk;
+		}
 	}
 
 	err = gpiochip_add_data(&bank->gpio_chip, bank);
@@ -1510,6 +1512,8 @@ int stm32_pctl_probe(struct platform_device *pdev)
 	pctl->domain = stm32_pctrl_get_irq_domain(pdev);
 	if (IS_ERR(pctl->domain))
 		return PTR_ERR(pctl->domain);
+	if (!pctl->domain)
+		dev_warn(dev, "pinctrl without interrupt support\n");
 
 	/* hwspinlock is optional */
 	hwlock_id = of_hwspin_lock_get_id(pdev->dev.of_node, 0);