Reviewed-by: Mohammed Thasleem <mohammed.thasleem@intel.com>
On 20-02-2026 08:52 pm, Kunal Joshi wrote:
Add a new subtest mst-suspend-read-crc that verifies MST outputs--> I think we can guard this using igt_debug() instead of igt_info().
preserve display content (via CRC comparison) across S3 suspend/resume.
The test enumerates all connected DP MST topologies, and for each root
connector exercises all non-empty subsets of the discovered MST outputs.
For each subset it:
- Assigns pipes and selects non-joiner modes
- Fits modes within bandwidth constraints
- Creates green FBs, commits, and collects pre-suspend CRCs
- Suspends to memory and resumes
- Collects post-suspend CRCs and asserts they match
v2:
- Add error handling for igt_pipe_crc_new (Thasleem)
- Improve log format with index for clarity (Thasleem)
- Order declarations in decreasing line length (Thasleem)
- Add print message when no MST found (Thasleem)
- Add bounds check for idx in subset loop (Thasleem)
- Use igt_crtc_crc_new() instead of igt_pipe_crc_new() (Ville)
v3:
- framebuffers missing in commit (Bilal)
v4:
- Drop cleanup framework
Signed-off-by: Kunal Joshi <kunal1.joshi@intel.com>
---
tests/kms_pipe_crc_basic.c | 314 +++++++++++++++++++++++++++++++++++++
tests/meson.build | 3 +
2 files changed, 317 insertions(+)
diff --git a/tests/kms_pipe_crc_basic.c b/tests/kms_pipe_crc_basic.c
index f7b6ec293..59a44e92e 100644
--- a/tests/kms_pipe_crc_basic.c
+++ b/tests/kms_pipe_crc_basic.c
@@ -32,7 +32,10 @@
#include "igt.h"
#include "igt_sysfs.h"
+#include "intel/kms_mst_helper.h"
+#include "intel/kms_joiner_helper.h"
#include <errno.h>
+#include <limits.h>
#include <stdbool.h>
#include <stdio.h>
#include <string.h>
@@ -77,6 +80,11 @@
* CRTC does not cause issues.
*/
+/**
+ * SUBTEST: mst-suspend-read-crc
+ * Description: MST suspend test for pipe CRC reads.
+ */
+
static bool extended;
static enum pipe active_pipes[IGT_MAX_PIPES];
static uint32_t last_pipe;
@@ -96,6 +104,306 @@ static struct {
{ .r = 0.0, .g = 1.0, .b = 1.0 },
};
+#define MAX_MST_OUTPUT 3
+
+static void collect_single_crc(igt_crtc_t *crtc, igt_crc_t *crc)
+{
+ igt_pipe_crc_t *pipe_crc;
+
+ pipe_crc = igt_crtc_crc_new(crtc, IGT_PIPE_CRC_SOURCE_AUTO);
+ igt_assert(pipe_crc);
+ igt_pipe_crc_collect_crc(pipe_crc, crc);
+ igt_pipe_crc_free(pipe_crc);
+}
+
+static void collect_crc_for_active_outputs(igt_output_t **outputs,
+ int num_outputs,
+ igt_crc_t *crcs,
+ bool post_suspend)
+{
+ int i;
+
+ for (i = 0; i < num_outputs; i++) {
+ igt_output_t *output = outputs[i];
+ igt_crtc_t *crtc = igt_output_get_driving_crtc(output);
+
+ if (post_suspend)
+ igt_require_f(crtc,
+ "POST-SUSPEND: no driving CRTC for %s (topology changed?)\n",
+ output->name);
+ else
+ igt_assert_f(crtc,
+ "PRE-SUSPEND: no driving CRTC for %s (bad pipe assignment?)\n",
+ output->name);
+
+ collect_single_crc(crtc, &crcs[i]);
+ }
+}
+
+static void wait_for_vblanks(igt_output_t **outputs, int num_outputs,
+ bool post_suspend)
+{
+ int i;
+
+ for (i = 0; i < num_outputs; i++) {
+ igt_crtc_t *crtc = igt_output_get_driving_crtc(outputs[i]);
+
+ if (post_suspend)
+ igt_require_f(crtc,
+ "POST-SUSPEND: no driving CRTC for %s during vblank wait (topology changed?)\n",
+ outputs[i]->name);
+ else
+ igt_assert_f(crtc,
+ "PRE-SUSPEND: no driving CRTC for %s during vblank wait (bad pipe assignment?)\n",
+ outputs[i]->name);
+
+ igt_wait_for_vblank(crtc);
+ }
+}
+
+static void log_crc_for_outputs(igt_output_t **outputs, int num_outputs,
+ igt_crc_t *crcs, const char *stage)
+{
+ int i;
+
+ for (i = 0; i < num_outputs; i++) {
+ igt_output_t *o = outputs[i];
+ drmModeModeInfo *m = igt_output_get_mode(o);
+ char *s = igt_crc_to_string(&crcs[i]);
+ igt_crtc_t *crtc = igt_output_get_driving_crtc(o);
+
+ igt_info("[%d] %s: output %s -> crtc %s, CRC %s, mode %dx%d@%d\n",
+ i, stage, o->name,
+ igt_crtc_name(crtc),
+ s,
+ m ? m->hdisplay : -1,
+ m ? m->vdisplay : -1,
+ m ? m->vrefresh : 0);
+ free(s);Variable naming -->'a' could be more descriptive, might be --> output_idx? or any suitable..
+ }
+}
+
+/*
+ * Select non-joiner modes for all outputs to ensure CRC collection works.
+ * Joiner configurations consume multiple pipes and are not yet validated here.
+ * Must be called before igt_fit_modes_in_bw() so that bandwidth fitting uses
+ * the correct (non-joiner) modes.
+ */
+static void select_non_joiner_modes(int drm_fd, igt_output_t **outputs,
+ int num_outputs)
+{
+ int max_dotclock = igt_get_max_dotclock(drm_fd);
+ int i;
+
+ if (max_dotclock <= 0)
+ max_dotclock = INT_MAX;
+
+ for (i = 0; i < num_outputs; i++) {
+ igt_output_t *output = outputs[i];
+ drmModeModeInfo non_joiner_mode;
+
+ igt_require_f(max_non_joiner_mode_found(drm_fd,
+ output->config.connector,
+ max_dotclock,
+ &non_joiner_mode),
+ "No non-joiner mode found for %s\n",
+ output->name);
+ igt_output_override_mode(output, &non_joiner_mode);
+ }
+}
+
+static void create_fbs_for_outputs(int drm_fd, igt_output_t **outputs,
+ int num_outputs, struct igt_fb *fbs)
+{
+ int i;
+
+ for (i = 0; i < num_outputs; i++) {
+ igt_output_t *output = outputs[i];
+ drmModeModeInfo *mode = igt_output_get_mode(output);
+ igt_plane_t *primary;
+
+ igt_require_f(mode, "No mode available for output %s\n", output->name);
+
+ primary = igt_output_get_plane_type(output, DRM_PLANE_TYPE_PRIMARY);
+
+ igt_create_color_fb(drm_fd,
+ mode->hdisplay, mode->vdisplay,
+ DRM_FORMAT_XRGB8888,
+ DRM_FORMAT_MOD_LINEAR,
+ 0.0, 1.0, 0.0, /* Green color */
+ &fbs[i]);
+ igt_plane_set_fb(primary, &fbs[i]);
+ }
+}
+
+static void run_mst_subset_and_verify(igt_display_t *display,
+ igt_output_t **active_outputs,
+ int num_active,
+ int n_crtcs,
+ uint32_t master_pipes_mask,
+ uint32_t valid_pipes_mask)
+{
+ igt_crc_t pre_crcs[MAX_MST_OUTPUT];
+ igt_crc_t post_crcs[MAX_MST_OUTPUT];
+ struct igt_fb fbs[MAX_MST_OUTPUT];
+ uint32_t used_pipes_mask = 0;
+ enum igt_suspend_test stest = SUSPEND_TEST_NONE;
+ int drm_fd = display->drm_fd;
+ int a;
+
+ igt_require_f(num_active <= n_crtcs,
+ "Not enough crtcs for MST subset\n");
+
+ igt_require(igt_assign_pipes_for_outputs(drm_fd,
+ active_outputs,
+ num_active,
+ n_crtcs,
+ &used_pipes_mask,
+ master_pipes_mask,
+ valid_pipes_mask));
+
+ select_non_joiner_modes(drm_fd, active_outputs, num_active);
+
+ igt_require_f(igt_fit_modes_in_bw(display),
+ "Unable to fit modes in bw\n");
+
+ create_fbs_for_outputs(drm_fd, active_outputs, num_active, fbs);
+
+ igt_display_commit2(display, COMMIT_ATOMIC);
+
+ /* rtcwake cmd is not supported on MTK devices */
+ if (is_mtk_device(drm_fd))
+ stest = SUSPEND_TEST_DEVICES;
+
+ igt_info("MST subset: %d outputs, n_crtcs=%d\n",
+ num_active, n_crtcs);
+
+ wait_for_vblanks(active_outputs, num_active, false);
+ wait_for_vblanks(active_outputs, num_active, false);
+
+ collect_crc_for_active_outputs(active_outputs,
+ num_active,
+ pre_crcs, false);
+
+ log_crc_for_outputs(active_outputs, num_active, pre_crcs, "PRE-SUSPEND");
+
+ igt_system_suspend_autoresume(SUSPEND_STATE_MEM, stest);
+
+ wait_for_vblanks(active_outputs, num_active, true);
+ wait_for_vblanks(active_outputs, num_active, true);
+
+ collect_crc_for_active_outputs(active_outputs,
+ num_active,
+ post_crcs, true);
+
+ log_crc_for_outputs(active_outputs, num_active, post_crcs, "POST-SUSPEND");
+
+ for (a = 0; a < num_active; a++)
+ igt_assert_crc_equal(&pre_crcs[a], &post_crcs[a]);
+
+ /* Detach FBs from planes and remove them to leave a clean state */
+ for (a = 0; a < num_active; a++) {
+ igt_plane_t *primary =
+ igt_output_get_plane_type(active_outputs[a],
+ DRM_PLANE_TYPE_PRIMARY);
+ igt_plane_set_fb(primary, NULL);
+ igt_remove_fb(drm_fd, &fbs[a]);
+ }
+}
+
+static void mst_suspend_read_crc(igt_display_t *display)
+{
+ int n_crtcs = igt_display_n_crtcs(display);
+ igt_output_t *active_outputs[MAX_MST_OUTPUT];
+ /*
+ * igt_find_all_mst_output_in_topology() internally caps
+ * discovery at IGT_MAX_PIPES entries, so this is the
+ * correct upper bound for the buffer.
+ */
+ igt_output_t *mst_outputs[IGT_MAX_PIPES];
+ /* Fixed upper bound for tracking traversed root connectors. */
+ int traversed_roots[IGT_MAX_PIPES] = { 0 };
+ int drm_fd = display->drm_fd;
+ uint32_t valid_pipes_mask = 0;
+ int num_mst, i, num_active;
+ uint32_t master_pipes_mask;
+ igt_output_t *output;
+ igt_crtc_t *crtc;
+ int num_roots = 0;
+
+ for_each_crtc(display, crtc)
+ valid_pipes_mask |= BIT(crtc->pipe);
+
+ igt_set_all_master_pipes_for_platform(display, &master_pipes_mask);
+
+ for_each_connected_output(display, output) {
+ int root_id;
+ bool root_seen = false;
+
+ root_id = igt_get_dp_mst_connector_id(output);
+ if (root_id < 0) {
+ igt_info("Skipping non-mst output %s\n", output->name);
+ continue;
+ }
+
+ for (i = 0; i < num_roots; i++)
+ if (traversed_roots[i] == root_id)
+ root_seen = true;
+
+ if (root_seen)
+ continue;
+
+ num_mst = 0;
+ igt_require(igt_find_all_mst_output_in_topology(drm_fd, display,
+ output, mst_outputs,
+ &num_mst) == 0);
+ igt_assert_f(num_mst <= IGT_MAX_PIPES,
+ "MST topology discovery overflow: num_mst=%d > IGT_MAX_PIPES=%d\n",
+ num_mst, IGT_MAX_PIPES);
+ if (num_mst == 0) {
+ igt_info("No MST outputs found in topology for output %s\n",
+ output->name);
+ igt_skip("No MST outputs found in topology\n");
+ }
+
+ if (num_roots < IGT_MAX_PIPES)
+ traversed_roots[num_roots++] = root_id;
+
+ if (num_mst > MAX_MST_OUTPUT)
+ num_mst = MAX_MST_OUTPUT;
+
+ igt_dynamic_f("mst-root-%d", root_id) {
+ int mask;
+
+ for (mask = 1; mask < (1 << num_mst); mask++) {
+ int bit, idx = 0;
+
+ /* build subset for this bitmask */
+ for (bit = 0; bit < num_mst; bit++) {
+ if (!(mask & (1 << bit)))
+ continue;
+
+ if (idx >= MAX_MST_OUTPUT)
+ break;
+
+ active_outputs[idx++] = mst_outputs[bit];
+ }
+
+ num_active = idx;
+ if (!num_active)
+ continue;
+
+ igt_display_reset(display);
+
+ run_mst_subset_and_verify(display, active_outputs,
+ num_active, n_crtcs,
+ master_pipes_mask,
+ valid_pipes_mask);
+ }
+ }
+ }
+}
+
static bool simulation_constraint(igt_crtc_t *crtc)
{
if (igt_run_in_simulation() && !extended &&
@@ -525,6 +833,12 @@ int igt_main_args("e", NULL, help_str, opt_handler, NULL)
}
}
+ igt_describe("MST suspend test for pipe CRC reads.");
+ igt_subtest_with_dynamic("mst-suspend-read-crc") {
+ igt_require(igt_display_has_mst_output(&data.display));
+ mst_suspend_read_crc(&data.display);
+ }
+
igt_fixture() {
igt_display_fini(&data.display);
drm_close_driver(data.drm_fd);
diff --git a/tests/meson.build b/tests/meson.build
index 7f356de9b..06c0d8e98 100644
--- a/tests/meson.build
+++ b/tests/meson.build
@@ -399,6 +399,9 @@ extra_sources = {
join_paths ('intel', 'kms_joiner_helper.c') ],
'kms_dsc': [ join_paths ('intel', 'kms_dsc_helper.c') ],
'kms_joiner': [ join_paths ('intel', 'kms_joiner_helper.c') ],
+ 'kms_pipe_crc_basic': [
+ join_paths ('intel', 'kms_mst_helper.c'),
+ join_paths ('intel', 'kms_joiner_helper.c') ],
'kms_psr2_sf': [ join_paths ('intel', 'kms_dsc_helper.c') ],
}