[PATCH i-g-t v7 48/48] tests/unigraf/unigraf_lt: Add test for link training

Louis Chauvet
2026-02-23T12:09:41Z

To test link training on various situation, add multiple link
training scenarios.

Reviewed-by: Kory Maincent <kory.maincent@bootlin.com>
Signed-off-by: Louis Chauvet <louis.chauvet@bootlin.com>
---
tests/unigraf/meson.build | 1 +
tests/unigraf/unigraf_lt.c | 183 +++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 184 insertions(+)

diff --git a/tests/unigraf/meson.build b/tests/unigraf/meson.build
index 4ef8c32151e4..22e64c0f389d 100644
--- a/tests/unigraf/meson.build
+++ b/tests/unigraf/meson.build
@@ -1,5 +1,6 @@
unigraf_progs = [
'unigraf_connectivity',
+ 'unigraf_lt',
]

foreach prog : unigraf_progs
diff --git a/tests/unigraf/unigraf_lt.c b/tests/unigraf/unigraf_lt.c
new file mode 100644
index 000000000000..81e6ecd3fae4
--- /dev/null
+++ b/tests/unigraf/unigraf_lt.c
@@ -0,0 +1,183 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright © 2026 Google
+ *
+ * Authors:
+ * Louis Chauvet <louis.chauvet@bootlin.com>
+ */
+
+#include <stdint.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include <xf86drm.h>
+#include <xf86drmMode.h>
+
+#include "drm_fourcc.h"
+#include "drmtest.h"
+#include "igt_aux.h"
+#include "igt_core.h"
+#include "igt_dp.h"
+#include "igt_edid.h"
+#include "igt_kms.h"
+#include "unigraf/unigraf.h"
+
+/**
+ * TEST: unigraf link training
+ * Category: Core
+ * Description: Testing DP link training with a unigraf device
+ *
+ * SUBTEST: unigraf-dp-lane-count
+ * Description: Make sure that the link training goes well for different lane count
+ *
+ * SUBTEST: unigraf-dp-link-rate
+ * Description: Make sure that the link training goes well for different link rates
+ */
+
+static void init_output_and_display_pattern(igt_display_t *display, igt_output_t *output)
+{
+ igt_crtc_t *crtc;
+ struct igt_fb fb;
+ igt_plane_t *primary;
+ drmModeModeInfo *mode;
+ int fb_id;
+
+ igt_modeset_disable_all_outputs(display);
+ igt_display_reset(display);
+
+ igt_output_set_crtc(output, 0);
+ crtc = igt_get_crtc_for_output(display, output);
+ igt_output_set_crtc(output, crtc);
+
+ /* Get the current mode */
+ mode = igt_output_get_mode(output);
+ igt_assert(mode);
+
+ /* Create a framebuffer with a solid color pattern */
+ fb_id = igt_create_color_pattern_fb(display->drm_fd, mode->hdisplay,
+ mode->vdisplay, DRM_FORMAT_XRGB8888,
+ DRM_FORMAT_MOD_LINEAR, 0, 0, 0, &fb);
+ igt_assert(fb_id > 0);
+
+ primary = igt_output_get_plane_type(output, DRM_PLANE_TYPE_PRIMARY);
+
+ igt_assert(primary);
+
+ igt_plane_set_size(primary, mode->hdisplay, mode->vdisplay);
+ igt_plane_set_fb(primary, &fb);
+ igt_output_override_mode(output, mode);
+
+ igt_display_commit2(display, COMMIT_ATOMIC);
+
+ /* Set the framebuffer to the plane */
+ igt_plane_set_fb(primary, &fb);
+
+ /* Set the plane properties atomically */
+ igt_plane_set_prop_value(primary, IGT_PLANE_FB_ID, fb.fb_id);
+ igt_plane_set_prop_value(primary, IGT_PLANE_CRTC_X, 0);
+ igt_plane_set_prop_value(primary, IGT_PLANE_CRTC_Y, 0);
+ igt_plane_set_prop_value(primary, IGT_PLANE_CRTC_W, mode->hdisplay);
+ igt_plane_set_prop_value(primary, IGT_PLANE_CRTC_H, mode->vdisplay);
+
+ /* Commit the changes atomically */
+ igt_display_commit_atomic(display, DRM_MODE_ATOMIC_ALLOW_MODESET, NULL);
+}
+
+IGT_TEST_DESCRIPTION("Test unigraf device functionality");
+int igt_main()
+{
+ int drm_fd = -1;
+ igt_display_t display;
+ igt_output_t *output;
+ drmModeConnectorPtr connector;
+ int i;
+
+ igt_fixture() {
+ drm_fd = drm_open_driver(DRIVER_ANY);
+ igt_assert(drm_fd >= 0);
+
+ igt_display_require(&display, drm_fd);
+ unigraf_require_device(drm_fd);
+
+ connector = unigraf_get_connector(drm_fd);
+ }
+
+ igt_subtest_with_dynamic("unigraf-dp-lane-count") {
+ int lane_counts[3] = {1, 2, 4};
+ int current_lanes;
+
+ for (i = 0; i < ARRAY_SIZE(lane_counts); i++) {
+ igt_dynamic_f("unigraf-dp-lane-count-%d", lane_counts[i]) {
+ unigraf_reset();
+ unigraf_set_max_lane_count(lane_counts[i]);
+ unigraf_hpd_pulse(500000);
+
+ igt_display_require_output(&display);
+ output = igt_output_from_connector(&display, connector);
+ igt_assert(output);
+ igt_dp_force_link_retrain(drm_fd, output, 2);
+ init_output_and_display_pattern(&display, output);
+
+ current_lanes = igt_dp_get_current_lane_count(drm_fd, output);
+ igt_assert_eq(current_lanes, lane_counts[i]);
+ }
+ }
+ }
+
+ igt_subtest_with_dynamic("unigraf-dp-link-rate") {
+ int rates[] = {UNIGRAF_RATE_1_62_GHZ,
+ UNIGRAF_RATE_2_7_GHZ,
+ UNIGRAF_RATE_5_4_GHZ,
+ UNIGRAF_RATE_6_75_GHZ,
+ UNIGRAF_RATE_8_10_GHZ};
+ int current_rate;
+ int max_supported_rate;
+
+ for (i = 0; i < ARRAY_SIZE(rates); i++) {
+ igt_dynamic_f("unigraf-dp-link-rate-%d", rates[i]) {
+ unigraf_reset();
+ unigraf_set_max_link_rate(rates[i]);
+ unigraf_hpd_pulse(1000000);
+ igt_display_require_output(&display);
+ igt_display_reset(&display);
+ igt_display_require_output(&display);
+ output = igt_output_from_connector(&display, connector);
+ igt_assert(output);
+ igt_dp_force_link_retrain(drm_fd, output, 2);
+
+ init_output_and_display_pattern(&display, output);
+
+ current_rate = igt_dp_get_max_link_rate(drm_fd, output);
+ max_supported_rate = igt_dp_get_max_supported_rate(drm_fd, output);
+ igt_require(max_supported_rate >= unigraf_rate_to_kbs(rates[i]));
+ igt_assert_eq(current_rate, unigraf_rate_to_kbs(rates[i]));
+ }
+ }
+ }
+
+ igt_subtest("unigraf-dp-link-suspend-resume") {
+ int current_rate, current_lanes;
+
+ unigraf_reset();
+ igt_display_require_output(&display);
+ igt_display_reset(&display);
+ igt_display_require_output(&display);
+ output = igt_output_from_connector(&display, connector);
+ igt_assert(output);
+
+ /* Get initial link parameters */
+ current_rate = igt_dp_get_current_link_rate(drm_fd, output);
+ current_lanes = igt_dp_get_current_lane_count(drm_fd, output);
+
+ /* Suspend the system */
+ igt_system_suspend_autoresume(SUSPEND_STATE_MEM, SUSPEND_TEST_NONE);
+
+ /* Verify link parameters are maintained */
+ igt_assert_eq(igt_dp_get_current_link_rate(drm_fd, output), current_rate);
+ igt_assert_eq(igt_dp_get_current_lane_count(drm_fd, output), current_lanes);
+ }
+
+ igt_fixture() {
+ igt_display_fini(&display);
+ close(drm_fd);
+ }
+}

--
2.52.0