[PATCH v7 2/4] tests/intel/xe_sysfs*: Restore values on test failure

[Jonathan Cavitt <jonathan.cavitt@intel.com>]

The tests xe_sysfs_preempt_timeout and xe_sysfs_timeslice_duration
modify the values of preempt_timeout_us and timeslice_duration_us,
respectively.  However, on a test failure, it is possible that these
values may remain in their modified states, resulting in the values
being used in future tests and causing unexpected behavior.

Save the respective modified values before starting the test and attempt
to restore the values on test exit.

v2:
- Fix some formatting issues (Kamil)
- Abort if value restore fails (Kamil)
- Directly call igt_sysfs_printf on exit to avoid duplicating on helper
  (Kamil)

v3:
- Do not compare potentially unassigned variable (Kamil)
- Whitespace and commit name fixes (Kamil)

v4:
- Fix igt_sysfs_scanf/printf usage in tests (Kamil)

Suggested-by: Kamil Konieczny <kamil.konieczny@linux.intel.com>
Signed-off-by: Jonathan Cavitt <jonathan.cavitt@intel.com>
CC: Vinay Belgaumkar <vinay.belgaumkar@intel.com>
Reviewed-by: Kamil Konieczny <kamil.konieczny@linux.intel.com>
---
 tests/intel/xe_sysfs_preempt_timeout.c    | 58 +++++++++++++++++++----
 tests/intel/xe_sysfs_timeslice_duration.c | 57 ++++++++++++++++++----
 2 files changed, 96 insertions(+), 19 deletions(-)

diff --git a/tests/intel/xe_sysfs_preempt_timeout.c b/tests/intel/xe_sysfs_preempt_timeout.c
index 7fa0dfcdf7..841c04b215 100644
--- a/tests/intel/xe_sysfs_preempt_timeout.c
+++ b/tests/intel/xe_sysfs_preempt_timeout.c
@@ -170,6 +170,7 @@ static void test_timeout(int fd, int engine, const char **property, uint16_t cla
 	set_preempt_timeout(engine, saved);
 }
 
+#define	MAX_GTS	8
 igt_main
 {
 	static const struct {
@@ -183,8 +184,10 @@ igt_main
 				       "preempt_timeout_min",
 				       "preempt_timeout_max"}, };
 	int count = sizeof(property) / sizeof(property[0]);
+	int gt_count = 0;
 	int fd = -1, sys_fd, gt;
-	int engines_fd = -1, gt_fd = -1;
+	int engines_fd[MAX_GTS], gt_fd[MAX_GTS];
+	unsigned int pts[MAX_GTS][XE_MAX_ENGINE_INSTANCE];
 
 	igt_fixture {
 		fd = drm_open_driver(DRIVER_XE);
@@ -192,26 +195,61 @@ igt_main
 		sys_fd = igt_sysfs_open(fd);
 		igt_require(sys_fd != -1);
 		close(sys_fd);
+
+		xe_for_each_gt(fd, gt) {
+			int *list, size;
+			igt_require(gt_count < MAX_GTS);
+
+			gt_fd[gt_count] = xe_sysfs_gt_open(fd, gt);
+			igt_require(gt_fd[gt_count] != -1);
+			engines_fd[gt_count] = openat(gt_fd[gt_count], "engines", O_RDONLY);
+			igt_require(engines_fd[gt_count] != -1);
+
+			list = igt_sysfs_get_engine_list(engines_fd[gt_count], &size);
+			igt_require(size > 0);
+
+			for (int i = 0; i < size; i++)
+				igt_require(igt_sysfs_scanf(list[i], "preempt_timeout_us", "%u",
+							    &pts[gt_count][i]) == 1);
+
+			igt_sysfs_free_engine_list(list, size);
+			gt_count++;
+		}
 	}
 
 	for (int i = 0; i < count; i++) {
 		for (typeof(*tests) *t = tests; t->name; t++) {
 			igt_subtest_with_dynamic_f("%s-%s", property[i][0], t->name) {
+				int j = 0;
 				xe_for_each_gt(fd, gt) {
-					gt_fd = xe_sysfs_gt_open(fd, gt);
-					igt_require(gt_fd != -1);
-					engines_fd = openat(gt_fd, "engines", O_RDONLY);
-					igt_require(engines_fd != -1);
-
-					igt_sysfs_engines(fd, engines_fd, gt, 1, property[i],
-									  t->fn);
-					close(engines_fd);
-					close(gt_fd);
+					int e = engines_fd[j];
+
+					igt_sysfs_engines(fd, e, gt, 1, property[i], t->fn);
+					j++;
 				}
 			}
 		}
 	}
 	igt_fixture {
+		for (int i = gt_count - 1; i >= 0; i--) {
+			int *list, size;
+			list = igt_sysfs_get_engine_list(engines_fd[i], &size);
+
+			for (int j = size - 1; j >= 0; j--) {
+				unsigned int store = UINT_MAX;
+
+				igt_assert_lte(0, igt_sysfs_printf(list[j], "preempt_timeout_us",
+								   "%u", pts[i][j]));
+				igt_sysfs_scanf(list[j], "preempt_timeout_us", "%u", &store);
+				igt_abort_on_f(store != pts[i][j],
+					       "preempt_timeout_us not restored!\n");
+			}
+
+			igt_sysfs_free_engine_list(list, size);
+			close(engines_fd[i]);
+			close(gt_fd[i]);
+		}
+
 		drm_close_driver(fd);
 	}
 }
diff --git a/tests/intel/xe_sysfs_timeslice_duration.c b/tests/intel/xe_sysfs_timeslice_duration.c
index cf95a3ac1c..22c543692c 100644
--- a/tests/intel/xe_sysfs_timeslice_duration.c
+++ b/tests/intel/xe_sysfs_timeslice_duration.c
@@ -142,6 +142,7 @@ static void test_timeout(int fd, int engine, const char **property, uint16_t cla
 	set_timeslice_duration(engine, saved);
 }
 
+#define	MAX_GTS	8
 igt_main
 {
 	static const struct {
@@ -155,8 +156,10 @@ igt_main
 				       "timeslice_duration_min",
 				       "timeslice_duration_max"}, };
 	int count = sizeof(property) / sizeof(property[0]);
+	int gt_count = 0;
 	int fd = -1, sys_fd, gt;
-	int engines_fd = -1, gt_fd = -1;
+	int engines_fd[MAX_GTS], gt_fd[MAX_GTS];
+	unsigned int tds[MAX_GTS][XE_MAX_ENGINE_INSTANCE];
 
 	igt_fixture {
 		fd = drm_open_driver(DRIVER_XE);
@@ -164,25 +167,61 @@ igt_main
 		sys_fd = igt_sysfs_open(fd);
 		igt_require(sys_fd != -1);
 		close(sys_fd);
+
+		xe_for_each_gt(fd, gt) {
+			int *list, size;
+			igt_require(gt_count < MAX_GTS);
+
+			gt_fd[gt_count] = xe_sysfs_gt_open(fd, gt);
+			igt_require(gt_fd[gt_count] != -1);
+			engines_fd[gt_count] = openat(gt_fd[gt_count], "engines", O_RDONLY);
+			igt_require(engines_fd[gt_count] != -1);
+
+			list = igt_sysfs_get_engine_list(engines_fd[gt_count], &size);
+			igt_require(size > 0);
+
+			for (int i = 0; i < size; i++)
+				igt_require(igt_sysfs_scanf(list[i], "timeslice_duration_us", "%u",
+							    &tds[gt_count][i]) == 1);
+
+			igt_sysfs_free_engine_list(list, size);
+			gt_count++;
+		}
 	}
 
 	for (int i = 0; i < count; i++) {
 		for (typeof(*tests) *t = tests; t->name; t++) {
 			igt_subtest_with_dynamic_f("%s-%s", property[i][0], t->name) {
+				int j = 0;
 				xe_for_each_gt(fd, gt) {
-					gt_fd = xe_sysfs_gt_open(fd, gt);
-					igt_require(gt_fd != -1);
-					engines_fd = openat(gt_fd, "engines", O_RDONLY);
-					igt_require(engines_fd != -1);
-					igt_sysfs_engines(fd, engines_fd, gt, 1, property[i],
-										 t->fn);
-					close(engines_fd);
-					close(gt_fd);
+					int e = engines_fd[j];
+
+					igt_sysfs_engines(fd, e, gt, 1, property[i], t->fn);
+					j++;
 				}
 			}
 		}
 	}
 	igt_fixture {
+		for (int i = gt_count - 1; i >= 0; i--) {
+			int *list, size;
+			list = igt_sysfs_get_engine_list(engines_fd[i], &size);
+
+			for (int j = size - 1; j >= 0; j--) {
+				unsigned int store = UINT_MAX;
+
+				igt_assert_lte(0, igt_sysfs_printf(list[j], "timeslice_duration_us",
+								   "%u", tds[i][j]));
+				igt_sysfs_scanf(list[j], "timeslice_duration_us", "%u", &store);
+				igt_abort_on_f(store != tds[i][j],
+					       "timeslice_duration_us not restored!\n");
+			}
+
+			igt_sysfs_free_engine_list(list, size);
+			close(engines_fd[i]);
+			close(gt_fd[i]);
+		}
+
 		drm_close_driver(fd);
 	}
 }
-- 
2.43.0