[PATCH 2/2] drivers: base: Add basic devm tests for platform devices

[Maxime Ripard]

Platform devices show some inconsistencies with how devm resources are
released when the device has been probed and when it hasn't. Let's add a
few tests to exercise thos paths and odd cases.

Signed-off-by: Maxime Ripard <maxime@xxxxxxxxxx>
---
 drivers/base/test/Makefile               |   1 +
 drivers/base/test/platform-device-test.c | 278 +++++++++++++++++++++++++++++++
 2 files changed, 279 insertions(+)

diff --git a/drivers/base/test/Makefile b/drivers/base/test/Makefile
index d589ca3fa8fc..e321dfc7e922 100644
--- a/drivers/base/test/Makefile
+++ b/drivers/base/test/Makefile
@@ -2,6 +2,7 @@
 obj-$(CONFIG_TEST_ASYNC_DRIVER_PROBE)	+= test_async_driver_probe.o
 
 obj-$(CONFIG_DM_KUNIT_TEST)	+= root-device-test.o
+obj-$(CONFIG_DM_KUNIT_TEST)	+= platform-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/platform-device-test.c b/drivers/base/test/platform-device-test.c
new file mode 100644
index 000000000000..2779c6dfac06
--- /dev/null
+++ b/drivers/base/test/platform-device-test.c
@@ -0,0 +1,278 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <kunit/resource.h>
+
+#include <linux/device.h>
+#include <linux/platform_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 void devm_device_action(void *ptr)
+{
+	struct test_priv *priv = ptr;
+
+	priv->release_done = true;
+	wake_up_interruptible(&priv->release_wq);
+}
+
+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);
+}
+
+#define RELEASE_TIMEOUT_MS	500
+
+static void platform_device_devm_register_unregister_test(struct kunit *test)
+{
+	struct platform_device *pdev;
+	struct test_priv *priv;
+	int ret;
+
+	priv = kunit_kzalloc(test, sizeof(*priv), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, priv);
+	init_waitqueue_head(&priv->release_wq);
+
+	pdev = platform_device_alloc(DEVICE_NAME, PLATFORM_DEVID_NONE);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, pdev);
+
+	ret = platform_device_add(pdev);
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	priv->dev = &pdev->dev;
+
+	ret = devm_add_action_or_reset(priv->dev, devm_device_action, priv);
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	platform_device_unregister(pdev);
+
+	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 platform_device_devm_register_get_put_unregister_test(struct kunit *test)
+{
+	struct platform_device *pdev;
+	struct test_priv *priv;
+	int ret;
+
+	priv = kunit_kzalloc(test, sizeof(*priv), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, priv);
+	init_waitqueue_head(&priv->release_wq);
+
+	pdev = platform_device_alloc(DEVICE_NAME, PLATFORM_DEVID_NONE);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, pdev);
+
+	ret = platform_device_add(pdev);
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	priv->dev = &pdev->dev;
+
+	get_device(priv->dev);
+
+	ret = devm_add_action_or_reset(priv->dev, devm_device_action, priv);
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	put_device(priv->dev);
+
+	platform_device_unregister(pdev);
+
+	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 platform_device_devm_register_get_unregister_with_devm_test(struct kunit *test)
+{
+	struct platform_device *pdev;
+	struct test_priv *priv;
+	int ret;
+
+	priv = kunit_kzalloc(test, sizeof(*priv), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, priv);
+	init_waitqueue_head(&priv->release_wq);
+
+	pdev = platform_device_alloc(DEVICE_NAME, PLATFORM_DEVID_NONE);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, pdev);
+
+	ret = platform_device_add(pdev);
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	priv->dev = &pdev->dev;
+
+	get_device(priv->dev);
+
+	ret = devm_add_action_or_reset(priv->dev, devm_put_device_action, priv);
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	platform_device_unregister(pdev);
+
+	ret = wait_event_interruptible_timeout(priv->release_wq, priv->release_done,
+					       msecs_to_jiffies(RELEASE_TIMEOUT_MS));
+	KUNIT_EXPECT_GT(test, ret, 0);
+}
+
+static int fake_probe(struct platform_device *pdev)
+{
+	struct test_priv *priv = platform_get_drvdata(pdev);
+
+	priv->probe_done = true;
+	wake_up_interruptible(&priv->release_wq);
+
+	return 0;
+}
+
+static struct platform_driver fake_driver = {
+	.probe	= fake_probe,
+	.driver = {
+		.name = DEVICE_NAME,
+	},
+};
+
+static void probed_platform_device_devm_register_unregister_test(struct kunit *test)
+{
+	struct platform_device *pdev;
+	struct test_priv *priv;
+	int ret;
+
+	priv = kunit_kzalloc(test, sizeof(*priv), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, priv);
+	init_waitqueue_head(&priv->release_wq);
+
+	ret = platform_driver_register(&fake_driver);
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	pdev = platform_device_alloc(DEVICE_NAME, PLATFORM_DEVID_NONE);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, pdev);
+
+	priv->dev = &pdev->dev;
+	platform_set_drvdata(pdev, priv);
+
+	ret = platform_device_add(pdev);
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	ret = wait_event_interruptible_timeout(priv->release_wq, priv->probe_done,
+					       msecs_to_jiffies(RELEASE_TIMEOUT_MS));
+	KUNIT_ASSERT_GT(test, ret, 0);
+
+	ret = devm_add_action_or_reset(priv->dev, devm_device_action, priv);
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	platform_device_unregister(pdev);
+
+	ret = wait_event_interruptible_timeout(priv->release_wq, priv->release_done,
+					       msecs_to_jiffies(RELEASE_TIMEOUT_MS));
+	KUNIT_EXPECT_GT(test, ret, 0);
+
+	platform_driver_unregister(&fake_driver);
+}
+
+static void probed_platform_device_devm_register_get_put_unregister_test(struct kunit *test)
+{
+	struct platform_device *pdev;
+	struct test_priv *priv;
+	int ret;
+
+	priv = kunit_kzalloc(test, sizeof(*priv), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, priv);
+	init_waitqueue_head(&priv->release_wq);
+
+	ret = platform_driver_register(&fake_driver);
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	pdev = platform_device_alloc(DEVICE_NAME, PLATFORM_DEVID_NONE);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, pdev);
+
+	priv->dev = &pdev->dev;
+	platform_set_drvdata(pdev, priv);
+
+	ret = platform_device_add(pdev);
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	ret = wait_event_interruptible_timeout(priv->release_wq, priv->probe_done,
+					       msecs_to_jiffies(RELEASE_TIMEOUT_MS));
+	KUNIT_ASSERT_GT(test, ret, 0);
+
+	get_device(priv->dev);
+
+	ret = devm_add_action_or_reset(priv->dev, devm_device_action, priv);
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	put_device(priv->dev);
+
+	platform_device_unregister(pdev);
+
+	ret = wait_event_interruptible_timeout(priv->release_wq, priv->release_done,
+					       msecs_to_jiffies(RELEASE_TIMEOUT_MS));
+	KUNIT_EXPECT_GT(test, ret, 0);
+
+	platform_driver_unregister(&fake_driver);
+}
+
+static void probed_platform_device_devm_register_get_unregister_with_devm_test(struct kunit *test)
+{
+	struct platform_device *pdev;
+	struct test_priv *priv;
+	int ret;
+
+	priv = kunit_kzalloc(test, sizeof(*priv), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, priv);
+	init_waitqueue_head(&priv->release_wq);
+
+	ret = platform_driver_register(&fake_driver);
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	pdev = platform_device_alloc(DEVICE_NAME, PLATFORM_DEVID_NONE);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, pdev);
+
+	priv->dev = &pdev->dev;
+	platform_set_drvdata(pdev, priv);
+
+	ret = platform_device_add(pdev);
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	ret = wait_event_interruptible_timeout(priv->release_wq, priv->probe_done,
+					       msecs_to_jiffies(RELEASE_TIMEOUT_MS));
+	KUNIT_ASSERT_GT(test, ret, 0);
+
+	get_device(priv->dev);
+
+	ret = devm_add_action_or_reset(priv->dev, devm_put_device_action, priv);
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	platform_device_unregister(pdev);
+
+	ret = wait_event_interruptible_timeout(priv->release_wq, priv->release_done,
+					       msecs_to_jiffies(RELEASE_TIMEOUT_MS));
+	KUNIT_EXPECT_GT(test, ret, 0);
+
+	platform_driver_unregister(&fake_driver);
+}
+
+static struct kunit_case platform_device_devm_tests[] = {
+	KUNIT_CASE(platform_device_devm_register_unregister_test),
+	KUNIT_CASE(platform_device_devm_register_get_put_unregister_test),
+	KUNIT_CASE(platform_device_devm_register_get_unregister_with_devm_test),
+	KUNIT_CASE(probed_platform_device_devm_register_unregister_test),
+	KUNIT_CASE(probed_platform_device_devm_register_get_put_unregister_test),
+	KUNIT_CASE(probed_platform_device_devm_register_get_unregister_with_devm_test),
+	{}
+};
+
+static struct kunit_suite platform_device_devm_test_suite = {
+	.name = "platform-device-devm",
+	.test_cases = platform_device_devm_tests,
+};
+
+kunit_test_suite(platform_device_devm_test_suite);

-- 
2.40.0