Re: [PATCH v2 4/6] genirq/test: Depend on SPARSE_IRQ

[Guenter Roeck]

On Fri, Aug 22, 2025 at 11:59:05AM -0700, Brian Norris wrote:
> Some architectures have a rather static IRQ layout, with a limited
> NR_IRQS. Without SPARSE_IRQ, we may not be able to allocate any new fake
> IRQs, and the test will fail. (This occurs on ARCH=m68k, for example.)
> 
> Additionally, managed-affinity is only supported with
> CONFIG_SPARSE_IRQ=y, so irq_shutdown_depth_test() and
> irq_cpuhotplug_test() would fail without it.
> 
> Add a 'SPARSE_IRQ' dependency to avoid these problems.
> 
> Many architectures 'select SPARSE_IRQ', so this is easy to miss.
> 
> Notably, this also excludes ARCH=um from running any of these tests,
> even though some of them might work.
> 
> Fixes: 66067c3c8a1e ("genirq: Add kunit tests for depth counts")
> Reported-by: Guenter Roeck <linux@xxxxxxxxxxxx>
> Signed-off-by: Brian Norris <briannorris@xxxxxxxxxxxx>

Tested-by: Guenter Roeck <linux@xxxxxxxxxxxx>

> ---
> 
> Changes in v2:
>  * Make all tests depend on SPARSE_IRQ, not just a few (resolves
>    ARCH=m68k issues)
> 
>  kernel/irq/Kconfig | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/kernel/irq/Kconfig b/kernel/irq/Kconfig
> index 08088b8e95ae..a75df2bb9db6 100644
> --- a/kernel/irq/Kconfig
> +++ b/kernel/irq/Kconfig
> @@ -147,6 +147,7 @@ config GENERIC_IRQ_KEXEC_CLEAR_VM_FORWARD
>  config IRQ_KUNIT_TEST
>  	bool "KUnit tests for IRQ management APIs" if !KUNIT_ALL_TESTS
>  	depends on KUNIT=y
> +	depends on SPARSE_IRQ
>  	default KUNIT_ALL_TESTS
>  	select IRQ_DOMAIN
>  	imply SMP
> -- 
> 2.51.0.rc2.233.g662b1ed5c5-goog
>