[PATCH] irqchip: fix compile-testing without CONFIG_OF

[Arnd Bergmann <arnd@kernel.org>]

From: Arnd Bergmann <arnd@arndb.de>

Drivers using the new IRQCHIP_PLATFORM_DRIVER_BEGIN helper
fail to link when compile-testing without CONFIG_OF,
as that means CONFIG_IRQCHIP is disabled as well:

ld.lld: error: undefined symbol: platform_irqchip_probe
>>> referenced by irq-meson-gpio.c
>>>               irqchip/irq-meson-gpio.o:(meson_gpio_intc_driver) in archive drivers/built-in.a
>>> referenced by irq-mchp-eic.c
>>>               irqchip/irq-mchp-eic.o:(mchp_eic_driver) in archive drivers/built-in.a

As the drivers are not actually used in this case, just
making the reference to this symbol conditional helps
avoid the link failure.

Fixes: f8410e626569 ("irqchip: Add IRQCHIP_PLATFORM_DRIVER_BEGIN/END and IRQCHIP_MATCH helper macros")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 include/linux/irqchip.h | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/include/linux/irqchip.h b/include/linux/irqchip.h
index 7f007b9c23f8..3a091d0710ae 100644
--- a/include/linux/irqchip.h
+++ b/include/linux/irqchip.h
@@ -48,8 +48,9 @@ static const struct of_device_id drv_name##_irqchip_match_table[] = {
 	{},								\
 };									\
 MODULE_DEVICE_TABLE(of, drv_name##_irqchip_match_table);		\
-static struct platform_driver drv_name##_driver = {		\
-	.probe  = platform_irqchip_probe,				\
+static struct platform_driver drv_name##_driver = {			\
+	.probe  = IS_ENABLED(CONFIG_IRQCHIP) ? 				\
+			platform_irqchip_probe : NULL,			\
 	.driver = {							\
 		.name = #drv_name,					\
 		.owner = THIS_MODULE,					\
-- 
2.29.2