[PATCH v2 3/3] driver core: platform: tests: add test cases for correct swnode removal

Bartosz Golaszewski
2026-04-23T12:12:27Z

Extend the kunit module for platform devices with test cases verifying
that the same software node can be added to platform devices repeatedly.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
---
drivers/base/test/platform-device-test.c | 106 +++++++++++++++++++++++++++++++
1 file changed, 106 insertions(+)

diff --git a/drivers/base/test/platform-device-test.c b/drivers/base/test/platform-device-test.c
index 6355a2231b741791b54eb78af42e13f31f745184..4b23f0d7f88548c62c49801fcee0919915e6e153 100644
--- a/drivers/base/test/platform-device-test.c
+++ b/drivers/base/test/platform-device-test.c
@@ -1,12 +1,15 @@
// SPDX-License-Identifier: GPL-2.0

+#include <kunit/fwnode.h>
#include <kunit/platform_device.h>
#include <kunit/resource.h>

#include <linux/device.h>
#include <linux/device/bus.h>
+#include <linux/fwnode.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
+#include <linux/property.h>

#define DEVICE_NAME "test"

@@ -253,9 +256,112 @@ static struct kunit_suite platform_device_match_test_suite = {
.test_cases = platform_device_match_tests,
};

+static int platform_device_swnode_test_probe(struct platform_device *pdev)
+{
+ return 0;
+}
+
+static struct platform_driver platform_swnode_test_driver = {
+ .probe = platform_device_swnode_test_probe,
+ .driver = {
+ .name = DEVICE_NAME,
+ },
+};
+
+static const struct software_node platform_device_test_swnode = { };
+
+/*
+ * Check that reusing a software node works correctly. If the call to
+ * platform_device_register_full() fails after adding the secondary firmware
+ * node, the software node must be unregistered in the device's release()
+ * callback or the subsequent call to platform_device_register_full() will fail
+ * with -EBUSY due to the software node aleady having been registered.
+ */
+static void platform_device_swnode_add_twice(struct kunit *test)
+{
+ struct platform_device_info pdevinfo;
+ struct platform_device *pdev;
+ struct fwnode_handle fwnode;
+ int ret;
+
+ ret = kunit_platform_driver_register(test, &platform_swnode_test_driver);
+ KUNIT_ASSERT_EQ(test, ret, 0);
+
+ fwnode_init(&fwnode, NULL);
+ pdevinfo = (struct platform_device_info){
+ .name = DEVICE_NAME,
+ .id = PLATFORM_DEVID_NONE,
+ .fwnode = &fwnode,
+ .swnode = &platform_device_test_swnode,
+ };
+
+ pdev = platform_device_register_full(&pdevinfo);
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, pdev);
+
+ wait_for_device_probe();
+ KUNIT_ASSERT_TRUE(test, device_is_bound(&pdev->dev));
+
+ platform_device_unregister(pdev);
+
+ pdev = platform_device_register_full(&pdevinfo);
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, pdev);
+
+ wait_for_device_probe();
+ KUNIT_ASSERT_TRUE(test, device_is_bound(&pdev->dev));
+
+ platform_device_unregister(pdev);
+}
+
+/*
+ * Check that passing a software node as the primary firmware node of the
+ * platform device does not result in it being unregistered by the call to
+ * device_remove_software_node() in its release path.
+ */
+static void platform_device_swnode_as_primary(struct kunit *test)
+{
+ struct platform_device_info pdevinfo;
+ struct platform_device *pdev;
+ struct fwnode_handle *fwnode;
+ int ret;
+
+ ret = kunit_platform_driver_register(test, &platform_swnode_test_driver);
+ KUNIT_ASSERT_EQ(test, ret, 0);
+
+ fwnode = kunit_software_node_register(test, &platform_device_test_swnode);
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, fwnode);
+
+ pdevinfo = (struct platform_device_info){
+ .name = DEVICE_NAME,
+ .id = PLATFORM_DEVID_NONE,
+ .fwnode = fwnode,
+ };
+
+ pdev = platform_device_register_full(&pdevinfo);
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, pdev);
+
+ wait_for_device_probe();
+ KUNIT_ASSERT_TRUE(test, device_is_bound(&pdev->dev));
+
+ platform_device_unregister(pdev);
+
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, software_node_fwnode(&platform_device_test_swnode));
+}
+
+static struct kunit_case platform_device_swnode_tests[] = {
+ KUNIT_CASE(platform_device_swnode_add_twice),
+ KUNIT_CASE(platform_device_swnode_as_primary),
+ {}
+};
+
+static struct kunit_suite platform_device_swnode_test_suite = {
+ .name = "platform-device-swnode",
+ .test_cases = platform_device_swnode_tests,
+};
+
kunit_test_suites(
&platform_device_devm_test_suite,
&platform_device_match_test_suite,
+ &platform_device_swnode_test_suite,
);

MODULE_DESCRIPTION("Test module for platform devices");

--
2.47.3