Re: [PATCH v8 8/8] clk: Add KUnit tests for clks registered with struct clk_parent_data

[Stephen Boyd <sboyd@kernel.org>]

Quoting Guenter Roeck (2024-10-03 21:52:09)
> On 10/3/24 17:42, Stephen Boyd wrote:
> > 
> > Can you please describe how you run the kunit test? And provide the qemu
> > command you run to boot arm64 with acpi?
> > 
> 
> Example command line:
> 
> qemu-system-aarch64 -M virt -m 512 \
>       -kernel arch/arm64/boot/Image -no-reboot -nographic \
>       -snapshot \
>       -bios /opt/buildbot/rootfs/arm64/../firmware/QEMU_EFI-aarch64.fd \
>       -device virtio-blk-device,drive=d0 \
>       -drive file=rootfs.ext2,if=none,id=d0,format=raw \
>       -cpu cortex-a57 -serial stdio -monitor none -no-reboot \
>       --append "kunit.stats_enabled=2 kunit.filter=speed>slow root=/dev/vda rootwait earlycon=pl011,0x9000000 console=ttyAMA0"
> 
> That works fine for me. Configuration is arm64 defconfig plus various
> debug and kunit options. I built the efi image myself from sources.
> The root file system is from buildroot with modified init script.
> kunit tests are all built into the kernel and run during boot.

Thanks. I figured out that I was missing enabling CONFIG_ACPI. Here's my
commandline

./tools/testing/kunit/kunit.py run --arch=arm64 \
	--kunitconfig=drivers/of \
	--qemu_args="-bios /usr/share/qemu-efi-aarch64/QEMU_EFI.fd -smp 2" \
	--kconfig_add="CONFIG_ACPI=y" \
	--kernel_args="earlycon=pl011,0x9000000"

Now I can boot and reproduce the failure, but there's another problem.
ACPI disables itself when it fails to find tables.

 ACPI: Unable to load the System Description Tables

This calls disable_acpi() which sets acpi_disabled to 1. This happens
before the unit test runs, meaning we can't reliably use 'acpi_disabled'
as a method to skip.

The best I can come up with then is to test for a NULL of_root when
CONFIG_ARM64 and CONFIG_ACPI are enabled, because the tests
intentionally don't work when both those configs are enabled and the
'of_root' isn't populated. In all other cases the 'of_root' missing is a
bug. I'll probably make this into some sort of kunit helper function in
of_private.h and send it to DT maintainers.

---8<----
diff --git a/drivers/of/of_kunit_helpers.c b/drivers/of/of_kunit_helpers.c
index 287d6c91bb37..a1330e183230 100644
--- a/drivers/of/of_kunit_helpers.c
+++ b/drivers/of/of_kunit_helpers.c
@@ -36,6 +36,9 @@ int of_overlay_fdt_apply_kunit(struct kunit *test, void *overlay_fdt,
 	int ret;
 	int *copy_id;
 
+	if (IS_ENABLED(CONFIG_ARM64) && IS_ENABLED(CONFIG_ACPI) && !of_root)
+		kunit_skip(test, "arm64+acpi rejects overlays");
+
 	copy_id = kunit_kmalloc(test, sizeof(*copy_id), GFP_KERNEL);
 	if (!copy_id)
 		return -ENOMEM;
diff --git a/drivers/of/of_test.c b/drivers/of/of_test.c
index c85a258bc6ae..6cca43bf8029 100644
--- a/drivers/of/of_test.c
+++ b/drivers/of/of_test.c
@@ -38,6 +38,8 @@ static int of_dtb_test_init(struct kunit *test)
 {
 	if (!IS_ENABLED(CONFIG_OF_EARLY_FLATTREE))
 		kunit_skip(test, "requires CONFIG_OF_EARLY_FLATTREE");
+	if (IS_ENABLED(CONFIG_ARM64) && IS_ENABLED(CONFIG_ACPI) && !of_root)
+		kunit_skip(test, "arm64+acpi doesn't populate a root node on ACPI systems");
 
 	return 0;
 }
diff --git a/drivers/of/overlay_test.c b/drivers/of/overlay_test.c
index 19a292cdeee3..3e7ac97a6796 100644
--- a/drivers/of/overlay_test.c
+++ b/drivers/of/overlay_test.c
@@ -64,6 +64,8 @@ static void of_overlay_apply_kunit_cleanup(struct kunit *test)
 
 	if (!IS_ENABLED(CONFIG_OF_EARLY_FLATTREE))
 		kunit_skip(test, "requires CONFIG_OF_EARLY_FLATTREE for root node");
+	if (IS_ENABLED(CONFIG_ARM64) && IS_ENABLED(CONFIG_ACPI) && !of_root)
+		kunit_skip(test, "arm64+acpi rejects overlays");
 
 	kunit_init_test(&fake, "fake test", NULL);
 	KUNIT_ASSERT_EQ(test, fake.status, KUNIT_SUCCESS);