[PATCH i-g-t v10 7/7] tests/intel/kms_pm_dc: Add dc3co-vpb-framegap subtest

[Jeevan B <jeevan.b@intel.com>]

Add a new subtest to validate DC3CO counter increments across
frame gaps exceeding the threshold during a video-like workload
with PSR2/PR enabled.

v2: Update commit message and test description.
v3: Remove TGL check for PSR2.

Signed-off-by: Jeevan B <jeevan.b@intel.com>
Reviewed-by: Mohammed Thasleem <mohammed.thasleem@intel.com>
---
 tests/intel/kms_pm_dc.c | 91 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 91 insertions(+)

diff --git a/tests/intel/kms_pm_dc.c b/tests/intel/kms_pm_dc.c
index d054d3b5c..9f79c2fa6 100644
--- a/tests/intel/kms_pm_dc.c
+++ b/tests/intel/kms_pm_dc.c
@@ -60,6 +60,10 @@
  *              exit cycle, ensuring DC3CO is not broken by deeper power state
  *              transitions.
  *
+ * SUBTEST: dc3co-vpb-framegap
+ * Description: Validate DC3CO counter increments before and after a delay greater
+ *              than 6 frame gaps during video-like load with PSR2 active.
+ *
  * SUBTEST: dc5-dpms
  * Description: Validate display engine entry to DC5 state while all connectors's
  *              DPMS property set to OFF
@@ -438,6 +442,63 @@ static void test_dc3co_framedrop(data_t *data)
 	cleanup_dc3co_fbs(data);
 }
 
+static void check_dc3co_with_framegap_load(data_t *data)
+{
+	igt_plane_t *primary;
+	uint32_t dc3co_cnt_before, dc3co_cnt_after_gap;
+	int delay, long_gap_us;
+	time_t secs = 3;
+	time_t start_time;
+
+	primary = igt_output_get_plane_type(data->output, DRM_PLANE_TYPE_PRIMARY);
+	igt_plane_set_fb(primary, NULL);
+
+	delay = 1.5 * ((1000 * 1000) / data->mode->vrefresh);
+
+	dc3co_cnt_before = igt_read_dc_counter(data->debugfs_fd,
+			   IGT_INTEL_CHECK_DC3CO);
+	start_time = time(NULL);
+	while (time(NULL) - start_time < secs) {
+		igt_plane_set_fb(primary, &data->fb_rgb);
+		igt_display_commit(&data->display);
+		usleep(delay);
+
+		igt_plane_set_fb(primary, &data->fb_rgr);
+		igt_display_commit(&data->display);
+		usleep(delay);
+	}
+
+	assert_dc_counter(data, IGT_INTEL_CHECK_DC3CO, dc3co_cnt_before);
+
+	long_gap_us = 7 * ((1000 * 1000) / data->mode->vrefresh);
+	usleep(long_gap_us);
+
+	dc3co_cnt_after_gap = igt_read_dc_counter(data->debugfs_fd,
+						  IGT_INTEL_CHECK_DC3CO);
+	start_time = time(NULL);
+	while (time(NULL) - start_time < secs) {
+		igt_plane_set_fb(primary, &data->fb_rgb);
+		igt_display_commit(&data->display);
+		usleep(delay);
+
+		igt_plane_set_fb(primary, &data->fb_rgr);
+		igt_display_commit(&data->display);
+		usleep(delay);
+	}
+
+	assert_dc_counter(data, IGT_INTEL_CHECK_DC3CO, dc3co_cnt_after_gap);
+}
+
+static void test_dc3co_vpb_framegap(data_t *data)
+{
+	igt_require_dc_counter(data->debugfs_fd, IGT_INTEL_CHECK_DC3CO);
+	setup_output(data);
+	setup_dc3co(data);
+	setup_videoplayback(data);
+	check_dc3co_with_framegap_load(data);
+	cleanup_dc3co_fbs(data);
+}
+
 static void test_dc5_retention_flops(data_t *data, int dc_flag)
 {
 	uint32_t dc_counter_before_psr;
@@ -896,6 +957,36 @@ int igt_main()
 		}
 	}
 
+	igt_describe("Validate DC3CO counter increments before and after a delay "
+		     "greater than 6 frame gaps during video-like load with PSR2/PR active");
+	igt_subtest_with_dynamic("dc3co-vpb-framegap") {
+		static const struct dc3co_test_mode dc3co_modes[] = {
+			{ PSR_MODE_2, "psr2" },
+			{ PR_MODE,    "pr"   },
+		};
+
+		for (int i = 0; i < ARRAY_SIZE(dc3co_modes); i++) {
+			const char *name = dc3co_modes[i].name;
+			data.op_psr_mode = dc3co_modes[i].mode;
+
+			igt_dynamic_f("%s", name) {
+				igt_require(psr_sink_support(data.drm_fd,
+						     data.debugfs_fd,
+						     data.op_psr_mode, NULL));
+
+				if (data.op_psr_mode == PSR_MODE_2)
+					igt_require_f(IS_TIGERLAKE(data.devid) ||
+						      intel_display_ver(data.devid) >= 35,
+						      "Platform does not support DC3CO with PSR2\n");
+				else
+					igt_require_f(intel_display_ver(data.devid) >= 35,
+						      "Platform does not support DC3CO with Panel Replay\n");
+
+				test_dc3co_vpb_framegap(&data);
+			}
+		}
+	}
+
 	igt_describe("This test validates display engine entry to DC5 state "
 		     "while PSR is active");
 	igt_subtest("dc5-psr") {
-- 
2.43.0