[igt-dev] [PATCH i-g-t] lib: Fix device lists not cleaned up sufficiently before rescan

[Janusz Krzysztofik]

Some effort is already taken to clean up previous content of device
lists before forced device rescan is performed but it is not
sufficient.  An attempt to use forced device rescan in a test results
in that test crashing or spinning until being killed by OOM killer.
Fix it.

Signed-off-by: Janusz Krzysztofik <janusz.krzysztofik at linux.intel.com>
---
 lib/igt_device_scan.c | 16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/lib/igt_device_scan.c b/lib/igt_device_scan.c
index b3f79c81e..db4da30d3 100644
--- a/lib/igt_device_scan.c
+++ b/lib/igt_device_scan.c
@@ -353,14 +353,11 @@ static void set_vendor_device(struct igt_device *dev)
 	dev->device = strndup(pci_id + 5, 4);
 }
 
-/* Allocate arrays for keeping scanned devices */
+/* Initialize lists for keeping scanned devices */
 static bool prepare_scan(void)
 {
-	if (igt_devs.all.prev == NULL || igt_devs.all.next == NULL)
-		IGT_INIT_LIST_HEAD(&igt_devs.all);
-
-	if (igt_devs.filtered.prev == NULL || igt_devs.filtered.next == NULL)
-		IGT_INIT_LIST_HEAD(&igt_devs.filtered);
+	IGT_INIT_LIST_HEAD(&igt_devs.all);
+	IGT_INIT_LIST_HEAD(&igt_devs.filtered);
 
 	return true;
 }
@@ -595,8 +592,15 @@ void igt_devices_scan(bool force)
 {
 	if (force && igt_devs.devs_scanned) {
 		struct igt_device *dev, *tmp;
+
+		igt_list_for_each_entry_safe(dev, tmp, &igt_devs.filtered,
+					     link) {
+			igt_list_del(&dev->link);
+			free(dev);
+		}
 		igt_list_for_each_entry_safe(dev, tmp, &igt_devs.all, link) {
 			igt_device_free(dev);
+			igt_list_del(&dev->link);
 			free(dev);
 		}
 
-- 
2.21.1