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@huawei.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240220111429.110666-1-chenjun102@huawei.com

diff --git a/drivers/irqchip/irq-mbigen.c b/drivers/irqchip/irq-mbigen.c
index 5101a3fb11df5bef53122db9db3c194669d754e7..58881d3139792074bf6ae1430a4de3760d3eb220 100644 (file)
--- 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);