The root devices show some odd behaviours compared to regular "bus" devices that have been probed through the usual mechanism, so let's create kunit tests to exercise those paths and odd cases.
It's not clear whether root devices are even allowed to use device managed resources, but the fact that it works in some cases but not others like shown in that test suite shouldn't happen either way: we want to make it consistent and documented.
These tests will (after the following patches) ensure that consistency and effectively document that it's allowed.
If it ever turns out to be a bad idea, we can always roll back and modify the tests then.
Reviewed-by: David Gow davidgow@google.com Signed-off-by: Maxime Ripard mripard@kernel.org --- drivers/base/test/.kunitconfig | 2 + drivers/base/test/Kconfig | 4 ++ drivers/base/test/Makefile | 2 + drivers/base/test/root-device-test.c | 110 +++++++++++++++++++++++++++++++++++ 4 files changed, 118 insertions(+)
diff --git a/drivers/base/test/.kunitconfig b/drivers/base/test/.kunitconfig new file mode 100644 index 000000000000..473923f0998b --- /dev/null +++ b/drivers/base/test/.kunitconfig @@ -0,0 +1,2 @@ +CONFIG_KUNIT=y +CONFIG_DM_KUNIT_TEST=y diff --git a/drivers/base/test/Kconfig b/drivers/base/test/Kconfig index 610a1ba7a467..9d42051f8f8e 100644 --- a/drivers/base/test/Kconfig +++ b/drivers/base/test/Kconfig @@ -9,6 +9,10 @@ config TEST_ASYNC_DRIVER_PROBE
If unsure say N.
+config DM_KUNIT_TEST + tristate "KUnit Tests for the device model" if !KUNIT_ALL_TESTS + depends on KUNIT + config DRIVER_PE_KUNIT_TEST bool "KUnit Tests for property entry API" if !KUNIT_ALL_TESTS depends on KUNIT=y diff --git a/drivers/base/test/Makefile b/drivers/base/test/Makefile index 7f76fee6f989..d589ca3fa8fc 100644 --- a/drivers/base/test/Makefile +++ b/drivers/base/test/Makefile @@ -1,5 +1,7 @@ # SPDX-License-Identifier: GPL-2.0 obj-$(CONFIG_TEST_ASYNC_DRIVER_PROBE) += test_async_driver_probe.o
+obj-$(CONFIG_DM_KUNIT_TEST) += root-device-test.o + obj-$(CONFIG_DRIVER_PE_KUNIT_TEST) += property-entry-test.o CFLAGS_property-entry-test.o += $(DISABLE_STRUCTLEAK_PLUGIN) diff --git a/drivers/base/test/root-device-test.c b/drivers/base/test/root-device-test.c new file mode 100644 index 000000000000..9a3e6cccae13 --- /dev/null +++ b/drivers/base/test/root-device-test.c @@ -0,0 +1,110 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright 2023 Maxime Ripard mripard@kernel.org + +#include <kunit/resource.h> + +#include <linux/device.h> + +#define DEVICE_NAME "test" + +struct test_priv { + bool probe_done; + bool release_done; + wait_queue_head_t release_wq; + struct device *dev; +}; + +static int root_device_devm_init(struct kunit *test) +{ + struct test_priv *priv; + + priv = kunit_kzalloc(test, sizeof(*priv), GFP_KERNEL); + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, priv); + init_waitqueue_head(&priv->release_wq); + + test->priv = priv; + + return 0; +} + +static void devm_device_action(void *ptr) +{ + struct test_priv *priv = ptr; + + priv->release_done = true; + wake_up_interruptible(&priv->release_wq); +} + +#define RELEASE_TIMEOUT_MS 100 + +/* + * Tests that a bus-less, non-probed device will run its device-managed + * actions when unregistered. + */ +static void root_device_devm_register_unregister_test(struct kunit *test) +{ + struct test_priv *priv = test->priv; + int ret; + + priv->dev = root_device_register(DEVICE_NAME); + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, priv->dev); + + ret = devm_add_action_or_reset(priv->dev, devm_device_action, priv); + KUNIT_ASSERT_EQ(test, ret, 0); + + root_device_unregister(priv->dev); + + ret = wait_event_interruptible_timeout(priv->release_wq, priv->release_done, + msecs_to_jiffies(RELEASE_TIMEOUT_MS)); + KUNIT_EXPECT_GT(test, ret, 0); +} + +static void devm_put_device_action(void *ptr) +{ + struct test_priv *priv = ptr; + + put_device(priv->dev); + priv->release_done = true; + wake_up_interruptible(&priv->release_wq); +} + +/* + * Tests that a bus-less, non-probed device will run its device-managed + * actions when unregistered, even if someone still holds a reference to + * it. + */ +static void root_device_devm_register_get_unregister_with_devm_test(struct kunit *test) +{ + struct test_priv *priv = test->priv; + int ret; + + kunit_skip(test, "This needs to be fixed in the core."); + + priv->dev = root_device_register(DEVICE_NAME); + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, priv->dev); + + get_device(priv->dev); + + ret = devm_add_action_or_reset(priv->dev, devm_put_device_action, priv); + KUNIT_ASSERT_EQ(test, ret, 0); + + root_device_unregister(priv->dev); + + ret = wait_event_interruptible_timeout(priv->release_wq, priv->release_done, + msecs_to_jiffies(RELEASE_TIMEOUT_MS)); + KUNIT_EXPECT_GT(test, ret, 0); +} + +static struct kunit_case root_device_devm_tests[] = { + KUNIT_CASE(root_device_devm_register_unregister_test), + KUNIT_CASE(root_device_devm_register_get_unregister_with_devm_test), + {} +}; + +static struct kunit_suite root_device_devm_test_suite = { + .name = "root-device-devm", + .init = root_device_devm_init, + .test_cases = root_device_devm_tests, +}; + +kunit_test_suite(root_device_devm_test_suite);