On Wed, 28 Jun 2023 at 17:49, Maxime Ripard mripard@kernel.org wrote:
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.
Signed-off-by: Maxime Ripard maxime@cerno.tech
Reviewed-by: David Gow davidgow@google.com
There's definitely an argument that root devices are not supposed to be like regular devices, and so devm_ managed resources aren't supposed to work with them. Either way: - It needs to be documented somewhere (and this test makes for good documentation, IMO). - It should be consistent: if devm_ isn't to be used with root devices, it should fail everywhere, and if it is, it should work in all the cases below.
So I'm all in favour of including this test and making root devices work.
That being said, I am planning to send out a patchset adding a struct kunit_device for use in tests, which will be attached to a "kunit" bus. I think the combination of "fix devm_ with root devices" and "don't recommend root devices as a 'fake' device for testing" is probably the longer-term solution everyone can agree upon?
Cheers, -- David
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_TESTSdepends on KUNIT
Could we add "default KUNIT_ALL_TESTS" here? Or if there's a good reason to not make this run by default, remove the "if !KUNIT_ALL_TESTS" condition above.
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);
-- 2.40.0