[PATCH v2 4/5] PM: runtime: Add tests for last_busy propagation

[Brian Norris]

This is a regression test for the problem fixed in "PM: runtime:
Propagate last_busy from dependent to dependency".

Signed-off-by: Brian Norris <briannorris at chromium.org>
---

Changes in v2:
 * Use device_move() instead of manual re-parenting
 * fsleep() instead of msleep()

 drivers/base/power/runtime-test.c | 99 +++++++++++++++++++++++++++++++
 1 file changed, 99 insertions(+)

diff --git a/drivers/base/power/runtime-test.c b/drivers/base/power/runtime-test.c
index 24865ce844fc..00ca3b10543a 100644
--- a/drivers/base/power/runtime-test.c
+++ b/drivers/base/power/runtime-test.c
@@ -4,6 +4,7 @@
  */
 
 #include <linux/cleanup.h>
+#include <linux/delay.h>
 #include <linux/pm_runtime.h>
 #include <linux/workqueue.h>
 #include <kunit/device.h>
@@ -285,6 +286,102 @@ static void pm_runtime_supplier_suspend_test(struct kunit *test)
 	KUNIT_EXPECT_TRUE(test, pm_runtime_suspended(norpm_supplier));
 }
 
+static void pm_runtime_parent_last_used_test(struct kunit *test)
+{
+	struct device *parent = kunit_device_register(test, DEVICE_NAME "_parent");
+	struct device *dev = kunit_device_register(test, DEVICE_NAME);
+	u64 expiry1, expiry2;
+
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, dev);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, parent);
+
+	KUNIT_ASSERT_EQ(test, 0, device_move(dev, parent, DPM_ORDER_NONE));
+
+	pm_runtime_set_active(parent);
+	pm_runtime_set_active(dev);
+	pm_runtime_use_autosuspend(parent);
+	pm_runtime_use_autosuspend(dev);
+
+	pm_runtime_set_autosuspend_delay(dev, 0);
+	/* Effectively infinite delay (prevent finishing autosuspend during this test). */
+	pm_runtime_set_autosuspend_delay(parent, 200000);
+
+	pm_runtime_mark_last_busy(dev);
+	pm_runtime_mark_last_busy(parent);
+
+	pm_runtime_get_noresume(dev);
+
+	pm_runtime_enable(parent);
+	pm_runtime_enable(dev);
+
+	expiry1 = pm_runtime_autosuspend_expiration(parent);
+	KUNIT_EXPECT_NE(test, 0, expiry1);
+
+	/* Make absolutely sure the clock advances. */
+	fsleep(1000);
+
+	KUNIT_EXPECT_EQ(test, 0, pm_runtime_put_sync_autosuspend(dev));
+
+	KUNIT_EXPECT_TRUE(test, pm_runtime_suspended(dev));
+
+	/* Flush, in case any request was pending. */
+	flush_workqueue(pm_wq);
+	KUNIT_EXPECT_FALSE(test, pm_runtime_suspended(parent));
+
+	expiry2 = pm_runtime_autosuspend_expiration(parent);
+	KUNIT_EXPECT_NE(test, 0, expiry2);
+	/* The child's last_busy time should have bumped up the parent's expiration. */
+	KUNIT_EXPECT_GT(test, expiry2, expiry1);
+}
+
+static void pm_runtime_supplier_last_used_test(struct kunit *test)
+{
+	struct device *supplier = kunit_device_register(test, DEVICE_NAME "_supplier");
+	struct device *dev = kunit_device_register(test, DEVICE_NAME);
+	u64 expiry1, expiry2;
+
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, dev);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, supplier);
+
+	KUNIT_ASSERT_NOT_NULL(test, device_link_add(dev, supplier, DL_FLAG_PM_RUNTIME));
+
+	pm_runtime_set_active(supplier);
+	pm_runtime_set_active(dev);
+	pm_runtime_use_autosuspend(supplier);
+	pm_runtime_use_autosuspend(dev);
+
+	pm_runtime_set_autosuspend_delay(dev, 0);
+	/* Effectively infinite delay (prevent finishing autosuspend during this test). */
+	pm_runtime_set_autosuspend_delay(supplier, 200000);
+
+	pm_runtime_mark_last_busy(dev);
+	pm_runtime_mark_last_busy(supplier);
+
+	pm_runtime_get_noresume(dev);
+
+	pm_runtime_enable(supplier);
+	pm_runtime_enable(dev);
+
+	expiry1 = pm_runtime_autosuspend_expiration(supplier);
+	KUNIT_EXPECT_NE(test, 0, expiry1);
+
+	/* Make absolutely sure the clock advances. */
+	fsleep(1000);
+
+	KUNIT_EXPECT_EQ(test, 0, pm_runtime_put_sync_autosuspend(dev));
+
+	KUNIT_EXPECT_TRUE(test, pm_runtime_suspended(dev));
+
+	/* Flush, in case any request was pending. */
+	flush_workqueue(pm_wq);
+	KUNIT_EXPECT_FALSE(test, pm_runtime_suspended(supplier));
+
+	expiry2 = pm_runtime_autosuspend_expiration(supplier);
+	KUNIT_EXPECT_NE(test, 0, expiry2);
+	/* The consumer's last_busy time should have bumped up the supplier's expiration. */
+	KUNIT_EXPECT_GT(test, expiry2, expiry1);
+}
+
 static struct kunit_case pm_runtime_test_cases[] = {
 	KUNIT_CASE(pm_runtime_depth_test),
 	KUNIT_CASE(pm_runtime_already_suspended_test),
@@ -293,6 +390,8 @@ static struct kunit_case pm_runtime_test_cases[] = {
 	KUNIT_CASE(pm_runtime_error_test),
 	KUNIT_CASE(pm_runtime_probe_active_test),
 	KUNIT_CASE(pm_runtime_supplier_suspend_test),
+	KUNIT_CASE(pm_runtime_parent_last_used_test),
+	KUNIT_CASE(pm_runtime_supplier_last_used_test),
 	{}
 };
 
-- 
2.56.0.398.g882cbad275-goog