[PATCH] tests/intel/xe_configfs: Reset configfs group after each subtest

[Nitin Gote <nitin.r.gote@intel.com>]

The xe_configfs test uses a shared configfs group across all subtests.
When subtests modify configfs attributes without resetting them, the
modified values persist and affect subsequent subtests. For example,
ctx-restore-mid-bb reports register value mismatches due to stale
batch buffer data from previous subtests.

Fix by removing the configfs device directory after each subtest and
letting the next subtest recreate it to get default values as
hardcoded in the driver.

Closes: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/6204
Signed-off-by: Nitin Gote <nitin.r.gote@intel.com>
---
v1->v2:
  Instead of manually resetting each attribute,
  it's cleaner to remove and recreate the configfs group after
  each subtests. (Michal)

 tests/intel/xe_configfs.c | 47 +++++++++++++++++++++++++++++++--------
 1 file changed, 38 insertions(+), 9 deletions(-)

diff --git a/tests/intel/xe_configfs.c b/tests/intel/xe_configfs.c
index d2dfd2e87..aa3435392 100644
--- a/tests/intel/xe_configfs.c
+++ b/tests/intel/xe_configfs.c
@@ -361,7 +361,6 @@ int igt_main()
 
 		configfs_fd = igt_configfs_open("xe");
 		igt_require(configfs_fd != -1);
-		configfs_device_fd = create_device_configfs_group(configfs_fd);
 		igt_install_exit_handler(restore);
 	}
 
@@ -369,39 +368,69 @@ int igt_main()
 	igt_subtest("survivability-mode") {
 		igt_require(IS_BATTLEMAGE(devid));
 		igt_require_f(!is_vf_device, "survivability mode not supported in VF\n");
+		configfs_device_fd = create_device_configfs_group(configfs_fd);
 		test_survivability_mode(configfs_device_fd);
+		close(configfs_device_fd);
+		igt_fs_remove_dir(configfs_fd, bus_addr);
 	}
 
 	igt_describe("Validate engines_allowed with invalid options");
-	igt_subtest("engines-allowed-invalid")
+	igt_subtest("engines-allowed-invalid") {
+		configfs_device_fd = create_device_configfs_group(configfs_fd);
 		test_engines_allowed_invalid(configfs_device_fd);
+		close(configfs_device_fd);
+		igt_fs_remove_dir(configfs_fd, bus_addr);
+	}
 
 	igt_describe("Validate engines_allowed");
-	igt_subtest("engines-allowed")
+	igt_subtest("engines-allowed") {
+		configfs_device_fd = create_device_configfs_group(configfs_fd);
 		test_engines_allowed(configfs_device_fd);
+		close(configfs_device_fd);
+		igt_fs_remove_dir(configfs_fd, bus_addr);
+	}
 
 	igt_describe("Validate gt_types_allowed");
-	igt_subtest("gt-types-allowed")
+	igt_subtest("gt-types-allowed") {
+		configfs_device_fd = create_device_configfs_group(configfs_fd);
 		test_gt_types_allowed(configfs_device_fd);
+		close(configfs_device_fd);
+		igt_fs_remove_dir(configfs_fd, bus_addr);
+	}
 
 	igt_describe("Validate ctx_restore_post_bb with invalid options");
-	igt_subtest("ctx-restore-post-bb-invalid")
+	igt_subtest("ctx-restore-post-bb-invalid") {
+		configfs_device_fd = create_device_configfs_group(configfs_fd);
 		test_ctx_restore_invalid(configfs_device_fd, "post");
+		close(configfs_device_fd);
+		igt_fs_remove_dir(configfs_fd, bus_addr);
+	}
 
 	igt_describe("Validate ctx_restore_post_bb");
-	igt_subtest("ctx-restore-post-bb")
+	igt_subtest("ctx-restore-post-bb") {
+		configfs_device_fd = create_device_configfs_group(configfs_fd);
 		test_ctx_restore(configfs_device_fd, "post");
+		close(configfs_device_fd);
+		igt_fs_remove_dir(configfs_fd, bus_addr);
+	}
 
 	igt_describe("Validate ctx_restore_mid_bb with invalid options");
-	igt_subtest("ctx-restore-mid-bb-invalid")
+	igt_subtest("ctx-restore-mid-bb-invalid") {
+		configfs_device_fd = create_device_configfs_group(configfs_fd);
 		test_ctx_restore_invalid(configfs_device_fd, "mid");
+		close(configfs_device_fd);
+		igt_fs_remove_dir(configfs_fd, bus_addr);
+	}
 
 	igt_describe("Validate ctx_restore_mid_bb");
-	igt_subtest("ctx-restore-mid-bb")
+	igt_subtest("ctx-restore-mid-bb") {
+		configfs_device_fd = create_device_configfs_group(configfs_fd);
 		test_ctx_restore(configfs_device_fd, "mid");
+		close(configfs_device_fd);
+		igt_fs_remove_dir(configfs_fd, bus_addr);
+	}
 
 	igt_fixture() {
-		close(configfs_device_fd);
 		close(configfs_fd);
 	}
 }
-- 
2.50.1