[igt-dev] [PATCH v3 i-g-t] tests/i915_pm_freq_api: Add a suspend subtest

[Vinay Belgaumkar <vinay.belgaumkar@intel.com>]

Verify that SLPC API works as expected after a suspend. Added
another subtest that does multiple GT resets and checks freq api
works as expected after each one.

We now check requested frequency instead of soft min/max after a
reset or suspend. That ensures the soft limits got applied
correctly at init. Also, disable efficient freq before starting the
test which allows current freq to be consistent with SLPC min freq.

v2: Restore freq in exit handler (Ashutosh)
v3: Free the allocated stash arrays

Signed-off-by: Vinay Belgaumkar <vinay.belgaumkar@intel.com>
---
 tests/i915/i915_pm_freq_api.c | 92 +++++++++++++++++++++++++++--------
 1 file changed, 71 insertions(+), 21 deletions(-)

diff --git a/tests/i915/i915_pm_freq_api.c b/tests/i915/i915_pm_freq_api.c
index 9005cd220..522abee35 100644
--- a/tests/i915/i915_pm_freq_api.c
+++ b/tests/i915/i915_pm_freq_api.c
@@ -18,6 +18,12 @@
  *
  * SUBTEST: freq-reset
  * Description: Test basic freq API works after a reset
+ *
+ * SUBTEST: freq-reset-multiple
+ * Description: Test basic freq API works after multiple resets
+ *
+ * SUBTEST: freq-suspend
+ * Description: Test basic freq API works after a runtime suspend
  */
 
 IGT_TEST_DESCRIPTION("Test SLPC freq API");
@@ -49,7 +55,6 @@ static void test_freq_basic_api(int dirfd, int gt)
 	rpn = get_freq(dirfd, RPS_RPn_FREQ_MHZ);
 	rp0 = get_freq(dirfd, RPS_RP0_FREQ_MHZ);
 	rpe = get_freq(dirfd, RPS_RP1_FREQ_MHZ);
-	igt_info("System min freq: %dMHz; max freq: %dMHz\n", rpn, rp0);
 
 	/*
 	 * Negative bound tests
@@ -79,31 +84,66 @@ static void test_freq_basic_api(int dirfd, int gt)
 
 }
 
-static void test_reset(int i915, int dirfd, int gt)
+static void test_reset(int i915, int dirfd, int gt, int count)
 {
 	uint32_t rpn = get_freq(dirfd, RPS_RPn_FREQ_MHZ);
 	int fd;
 
+	for (int i = 0; i < count; i++) {
+		igt_assert_f(set_freq(dirfd, RPS_MIN_FREQ_MHZ, rpn) > 0,
+			     "Failed after %d good cycles\n", i);
+		igt_assert_f(set_freq(dirfd, RPS_MAX_FREQ_MHZ, rpn) > 0,
+			     "Failed after %d good cycles\n", i);
+		usleep(ACT_FREQ_LATENCY_US);
+		igt_assert_f(get_freq(dirfd, RPS_CUR_FREQ_MHZ) == rpn,
+			     "Failed after %d good cycles\n", i);
+
+		/* Manually trigger a GT reset */
+		fd = igt_debugfs_gt_open(i915, gt, "reset", O_WRONLY);
+		igt_require(fd >= 0);
+		igt_ignore_warn(write(fd, "1\n", 2));
+
+		igt_assert_f(get_freq(dirfd, RPS_CUR_FREQ_MHZ) == rpn,
+			     "Failed after %d good cycles\n", i);
+	}
+	close(fd);
+}
+
+static void test_suspend(int i915, int dirfd, int gt)
+{
+	uint32_t rpn = get_freq(dirfd, RPS_RPn_FREQ_MHZ);
+
 	igt_assert(set_freq(dirfd, RPS_MIN_FREQ_MHZ, rpn) > 0);
 	igt_assert(set_freq(dirfd, RPS_MAX_FREQ_MHZ, rpn) > 0);
 	usleep(ACT_FREQ_LATENCY_US);
-	igt_assert(get_freq(dirfd, RPS_MIN_FREQ_MHZ) == rpn);
+	igt_assert(get_freq(dirfd, RPS_CUR_FREQ_MHZ) == rpn);
 
-	/* Manually trigger a GT reset */
-	fd = igt_debugfs_gt_open(i915, gt, "reset", O_WRONLY);
-	igt_require(fd >= 0);
-	igt_ignore_warn(write(fd, "1\n", 2));
-	close(fd);
+	/* Manually trigger a suspend */
+	igt_system_suspend_autoresume(SUSPEND_STATE_S3,
+				      SUSPEND_TEST_NONE);
 
-	igt_assert(get_freq(dirfd, RPS_MIN_FREQ_MHZ) == rpn);
-	igt_assert(get_freq(dirfd, RPS_MAX_FREQ_MHZ) == rpn);
+	igt_assert(get_freq(dirfd, RPS_CUR_FREQ_MHZ) == rpn);
 }
 
-igt_main
+int i915 = -1;
+uint32_t *stash_min, *stash_max;
+
+static void restore_sysfs_freq(int sig)
 {
-	int i915 = -1;
-	uint32_t *stash_min, *stash_max;
+	int dirfd, gt;
+	/* Restore frequencies */
+	for_each_sysfs_gt_dirfd(i915, dirfd, gt) {
+		igt_pm_ignore_slpc_efficient_freq(i915, dirfd, false);
+		igt_assert(set_freq(dirfd, RPS_MAX_FREQ_MHZ, stash_max[gt]) > 0);
+		igt_assert(set_freq(dirfd, RPS_MIN_FREQ_MHZ, stash_min[gt]) > 0);
+	}
+	free(stash_min);
+	free(stash_max);
+	close(i915);
+}
 
+igt_main
+{
 	igt_fixture {
 		int num_gts, dirfd, gt;
 
@@ -122,7 +162,9 @@ igt_main
 		for_each_sysfs_gt_dirfd(i915, dirfd, gt) {
 			stash_min[gt] = get_freq(dirfd, RPS_MIN_FREQ_MHZ);
 			stash_max[gt] = get_freq(dirfd, RPS_MAX_FREQ_MHZ);
+			igt_pm_ignore_slpc_efficient_freq(i915, dirfd, true);
 		}
+		igt_install_exit_handler(restore_sysfs_freq);
 	}
 
 	igt_describe("Test basic API for controlling min/max GT frequency");
@@ -140,16 +182,24 @@ igt_main
 
 		for_each_sysfs_gt_dirfd(i915, dirfd, gt)
 			igt_dynamic_f("gt%u", gt)
-				test_reset(i915, dirfd, gt);
+				test_reset(i915, dirfd, gt, 1);
 	}
 
-	igt_fixture {
+	igt_describe("Test basic freq API works after multiple resets");
+	igt_subtest_with_dynamic_f("freq-reset-multiple") {
 		int dirfd, gt;
-		/* Restore frequencies */
-		for_each_sysfs_gt_dirfd(i915, dirfd, gt) {
-			igt_assert(set_freq(dirfd, RPS_MAX_FREQ_MHZ, stash_max[gt]) > 0);
-			igt_assert(set_freq(dirfd, RPS_MIN_FREQ_MHZ, stash_min[gt]) > 0);
-		}
-		close(i915);
+
+		for_each_sysfs_gt_dirfd(i915, dirfd, gt)
+			igt_dynamic_f("gt%u", gt)
+				test_reset(i915, dirfd, gt, 50);
+	}
+
+	igt_describe("Test basic freq API works after suspend");
+	igt_subtest_with_dynamic_f("freq-suspend") {
+		int dirfd, gt;
+
+		for_each_sysfs_gt_dirfd(i915, dirfd, gt)
+			igt_dynamic_f("gt%u", gt)
+				test_suspend(i915, dirfd, gt);
 	}
 }
-- 
2.38.1