[PATCH i-g-t 17/20] tests/core_hotunplug: Add unbind-unplug-restore variant

[Janusz Krzysztofik]

Check if this 3-step procedure exhibits any issues with device recovery
after unplug.  Such issues may indicate insufficient device hardware
re-initialization performed by the device driver, or other kernel bugs
outside the driver code.

v2: rebase on upstream
v3: rebase on top of "Fixes and enhancements"

Signed-off-by: Janusz Krzysztofik <janusz.krzysztofik at linux.intel.com>
---
 tests/core_hotunplug.c | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/tests/core_hotunplug.c b/tests/core_hotunplug.c
index bc23e8c05..fdd67fe26 100644
--- a/tests/core_hotunplug.c
+++ b/tests/core_hotunplug.c
@@ -282,6 +282,17 @@ static void unbind_rebind(struct hotunplug *priv)
 	driver_bind(priv);
 }
 
+static void unbind_unplug_restore(struct hotunplug *priv)
+{
+	priv->failure = "subtest failure";
+
+	driver_unbind(priv, "");
+
+	device_unplug(priv, "");
+
+	device_restore(priv);
+}
+
 static void unplug_restore(struct hotunplug *priv)
 {
 	priv->failure = "subtest failure";
@@ -380,6 +391,18 @@ igt_main
 			recover(&priv);
 	}
 
+	igt_fixture
+		post_healthcheck(&priv);
+
+	igt_subtest_group {
+		igt_describe("Check if a device with the driver unbound from it can be cleanly restored after being unplugged\n");
+		igt_subtest("unbind-unplug-restore")
+			unbind_unplug_restore(&priv);
+
+		igt_fixture
+			recover(&priv);
+	}
+
 	igt_fixture
 		post_healthcheck(&priv);
 
-- 
2.21.1