[tip: irq/urgent] irqchip/mbigen: Don't use bus_get_dev_root() to find the parent

[tip-bot2 for Chen Jun]

The following commit has been merged into the irq/urgent branch of tip:

Commit-ID:     fb33a46cd75e18773dd5a414744507d84ae90870
Gitweb:        https://git.kernel.org/tip/fb33a46cd75e18773dd5a414744507d84ae90870
Author:        Chen Jun <chenjun102@xxxxxxxxxx>
AuthorDate:    Tue, 20 Feb 2024 19:14:29 +08:00
Committer:     Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitterDate: Wed, 21 Feb 2024 18:40:00 +01:00

irqchip/mbigen: Don't use bus_get_dev_root() to find the parent

bus_get_dev_root() returns sp->dev_root which is set in subsys_register(),
but subsys_register() is not called by platform_bus_init().

Therefor for the platform_bus_type, bus_get_dev_root() always returns NULL.
This makes mbigen_of_create_domain() always return -ENODEV.

Don't try to retrieve the parent via bus_get_dev_root() and
unconditionally hand a NULL pointer to of_platform_device_create() to
fix this.

Fixes: fea087fc291b ("irqchip/mbigen: move to use bus_get_dev_root()")
Signed-off-by: Chen Jun <chenjun102@xxxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Link: https://lore.kernel.org/r/20240220111429.110666-1-chenjun102@xxxxxxxxxx

---
 drivers/irqchip/irq-mbigen.c | 8 +-------
 1 file changed, 1 insertion(+), 7 deletions(-)

diff --git a/drivers/irqchip/irq-mbigen.c b/drivers/irqchip/irq-mbigen.c
index 5101a3f..58881d3 100644
--- a/drivers/irqchip/irq-mbigen.c
+++ b/drivers/irqchip/irq-mbigen.c
@@ -235,22 +235,17 @@ static const struct irq_domain_ops mbigen_domain_ops = {
 static int mbigen_of_create_domain(struct platform_device *pdev,
 				   struct mbigen_device *mgn_chip)
 {
-	struct device *parent;
 	struct platform_device *child;
 	struct irq_domain *domain;
 	struct device_node *np;
 	u32 num_pins;
 	int ret = 0;
 
-	parent = bus_get_dev_root(&platform_bus_type);
-	if (!parent)
-		return -ENODEV;
-
 	for_each_child_of_node(pdev->dev.of_node, np) {
 		if (!of_property_read_bool(np, "interrupt-controller"))
 			continue;
 
-		child = of_platform_device_create(np, NULL, parent);
+		child = of_platform_device_create(np, NULL, NULL);
 		if (!child) {
 			ret = -ENOMEM;
 			break;
@@ -273,7 +268,6 @@ static int mbigen_of_create_domain(struct platform_device *pdev,
 		}
 	}
 
-	put_device(parent);
 	if (ret)
 		of_node_put(np);