gpio: mxc: fix race between gpiochip registration and IRQ domain setup
devm_gpiochip_add_data() makes the GPIO chip visible to consumers
immediately. Since the chip sets .to_irq = mxc_gpio_to_irq, which calls
irq_find_mapping(port->domain, offset), any to_irq() call between
gpiochip registration and IRQ domain creation will operate on a NULL
domain.
Fix by moving devm_gpiochip_add_data() after the IRQ domain and generic
irq chip are fully initialized, ensuring port->domain and the irq chip
handlers are ready before the chip becomes visible to consumers.
Fixes: d37a65bb4663 ("gpio/mxc: Move Freescale MXC gpio driver to drivers/gpio")
Signed-off-by: Peng Fan <peng.fan@nxp.com>
Reviewed-by: Linus Walleij <linusw@kernel.org>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Reviewed-by: Andy Shevchenko <andy@kernel.org>
Link: https://patch.msgid.link/20261013-gpio-mxc-cleanup-v7-4-c4d769587d3e@nxp.com
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
diff --git a/drivers/gpio/gpio-mxc.c b/drivers/gpio/gpio-mxc.c
index e3a80f1..32ded7b 100644
--- a/drivers/gpio/gpio-mxc.c
+++ b/drivers/gpio/gpio-mxc.c
@@ -500,10 +500,6 @@ static int mxc_gpio_probe(struct platform_device *pdev)
else /* silence boot time warning */
port->gen_gc.gc.base = -1;
- err = devm_gpiochip_add_data(&pdev->dev, &port->gen_gc.gc, port);
- if (err)
- goto out_bgio;
-
irq_base = devm_irq_alloc_descs(&pdev->dev, -1, 0, 32, numa_node_id());
if (irq_base < 0) {
err = irq_base;
@@ -524,6 +520,15 @@ static int mxc_gpio_probe(struct platform_device *pdev)
if (err < 0)
goto out_irqdomain_remove;
+ /*
+ * Register the GPIO chip last: devm_gpiochip_add_data() makes the
+ * chip visible to consumers immediately, so the IRQ domain and
+ * generic irq chip must be ready before any to_irq() call.
+ */
+ err = devm_gpiochip_add_data(&pdev->dev, &port->gen_gc.gc, port);
+ if (err)
+ goto out_irqdomain_remove;
+
list_add_tail(&port->node, &mxc_gpio_ports);
mxc_update_irq_chained_handler(port, true);
