[RFC i-g-t 3/5] Add tests: core_debugfs and core_debugfs_display_on_off

[Peter Senna Tschudin <peter.senna@linux.intel.com>]

Introduces two GPU-agnostic tests, core_debugfs and
core_debugfs_display_on_off. These tests are designed to function with
any GPU, not limited to i915 and Xe.

core_debugfs: Attempts to open every file in debugfs associated with the
GPU.

core_debugfs_display_on_off: Powers on all available displays before
reading debugfs files, and then powers off all displays before reading
the files again.

Cc: marcin.bernatowicz@intel.com
Cc: himanshu.girotra@intel.com
Cc: aditya.chauhan@intel.com
Cc: pravalika.gurram@intel.com
Cc: sai.gowtham.ch@intel.com
Cc: ramadevi.gandi@intel.com
Cc: lucas.demarchi@intel.com
Cc: rodrigo.vivi@intel.com
Cc: kamil.konieczny@linux.intel.com
Cc: katarzyna.piecielska@intel.com
Signed-off-by: Peter Senna Tschudin <peter.senna@linux.intel.com>
---
 tests/core_debugfs.c                |  47 ++++++++
 tests/core_debugfs_display_on_off.c | 165 ++++++++++++++++++++++++++++
 tests/meson.build                   |   2 +
 3 files changed, 214 insertions(+)
 create mode 100644 tests/core_debugfs.c
 create mode 100644 tests/core_debugfs_display_on_off.c

diff --git a/tests/core_debugfs.c b/tests/core_debugfs.c
new file mode 100644
index 000000000..a5cd44ffa
--- /dev/null
+++ b/tests/core_debugfs.c
@@ -0,0 +1,47 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright © 2025 Intel Corporation
+ */
+
+#include "igt.h"
+#include "igt_debugfs.h"
+#include "igt_dir_explorer.h"
+
+/**
+ * TEST: debugfs test
+ * Description: Read entries from debugfs
+ * Category: Core
+ * Mega feature: General Core features
+ * Sub-category: uapi
+ * Functionality: debugfs
+ * Feature: core
+ * Test category: uapi
+ *
+ * SUBTEST: debugfs-read-all-entries
+ * Description: Read all entries from debugfs path validating debugfs entries
+ */
+
+IGT_TEST_DESCRIPTION("Read entries from debugfs");
+
+igt_main
+{
+	int debugfs = -1;
+	int fd = -1;
+
+	igt_fixture {
+		fd = drm_open_driver_master(DRIVER_ANY);
+		debugfs = igt_debugfs_dir(fd);
+		igt_require(debugfs >= 0);
+
+		kmstest_set_vt_graphics_mode();
+	}
+
+	igt_describe("Read all entries from debugfs path.");
+	igt_subtest("debugfs-read-all-entries")
+		igt_dir_explorer_read_and_discard_all(debugfs, 0);
+
+	igt_fixture {
+		close(debugfs);
+		drm_close_driver(fd);
+	}
+}
diff --git a/tests/core_debugfs_display_on_off.c b/tests/core_debugfs_display_on_off.c
new file mode 100644
index 000000000..2dca24996
--- /dev/null
+++ b/tests/core_debugfs_display_on_off.c
@@ -0,0 +1,165 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright © 2025 Intel Corporation
+ */
+
+#include "igt.h"
+#include "igt_debugfs.h"
+#include "igt_dir_explorer.h"
+
+/**
+ * TEST: debugfs display on/off test
+ * Description: Read entries from debugfs, and sysfs paths.
+ * Category: Core
+ * Mega feature: General Core features
+ * Sub-category: uapi
+ * Functionality: debugfs
+ * Feature: core
+ * Test category: uapi
+ *
+ * SUBTEST: debugfs-read-all-entries-display-off
+ * Description: Read all debugfs entries with display off.
+ *
+ * SUBTEST: debugfs-read-all-entries-display-on
+ * Description: Read all debugfs entries with display on.
+ */
+
+/** bool igt_kms_all_displays_on: Try to turn on all displays
+ * @fd: file descriptor for the drm device
+ *
+ * Returns: void
+ */
+static void igt_display_all_on(igt_display_t *display)
+{
+	struct igt_fb fb[IGT_MAX_PIPES];
+	enum pipe pipe;
+	int ret;
+
+	/* try to light all pipes */
+retry:
+	for_each_pipe(display, pipe) {
+		igt_output_t *output;
+
+		for_each_valid_output_on_pipe(display, pipe, output) {
+			igt_plane_t *primary;
+			drmModeModeInfo *mode;
+
+			if (output->pending_pipe != PIPE_NONE)
+				continue;
+
+			igt_output_set_pipe(output, pipe);
+			primary = igt_output_get_plane_type(output, DRM_PLANE_TYPE_PRIMARY);
+			mode = igt_output_get_mode(output);
+			igt_create_pattern_fb(display->drm_fd,
+						mode->hdisplay, mode->vdisplay,
+						DRM_FORMAT_XRGB8888,
+						DRM_FORMAT_MOD_LINEAR, &fb[pipe]);
+
+			/* Set a valid fb as some debugfs like to
+			 * inspect it on a active pipe
+			 */
+			igt_plane_set_fb(primary, &fb[pipe]);
+			break;
+		}
+	}
+
+	if (display->is_atomic)
+		ret = igt_display_try_commit_atomic(display,
+				DRM_MODE_ATOMIC_TEST_ONLY |
+				DRM_MODE_ATOMIC_ALLOW_MODESET,
+				NULL);
+	else
+		ret = igt_display_try_commit2(display, COMMIT_LEGACY);
+
+	if (ret) {
+		igt_output_t *output;
+		bool found = igt_override_all_active_output_modes_to_fit_bw(display);
+
+		igt_require_f(found, "No valid mode combo found.\n");
+
+		for_each_connected_output(display, output)
+			igt_output_set_pipe(output, PIPE_NONE);
+
+		goto retry;
+	}
+
+	igt_display_commit2(display, display->is_atomic ? COMMIT_ATOMIC : COMMIT_LEGACY);
+}
+
+/** bool igt_kms_all_displays_off: Try to turn off all displays
+ * @fd: file descriptor for the drm device
+ *
+ * Returns: void
+ */
+static void igt_display_all_off(igt_display_t *display)
+{
+	enum pipe pipe;
+	igt_output_t *output;
+	igt_plane_t *plane;
+
+	for_each_connected_output(display, output)
+		igt_output_set_pipe(output, PIPE_NONE);
+
+	for_each_pipe(display, pipe)
+		for_each_plane_on_pipe(display, pipe, plane)
+			igt_plane_set_fb(plane, NULL);
+
+	igt_display_commit2(display, display->is_atomic ? COMMIT_ATOMIC : COMMIT_LEGACY);
+}
+
+static void kms_tests(int fd, int debugfs)
+{
+	igt_display_t *display;
+	char test_name[64];
+
+	display = calloc(1, sizeof(*display));
+
+	igt_fixture
+		igt_display_require(display, fd);
+
+	snprintf(test_name, sizeof(test_name),
+		 "debugfs-read-all-entries-display-on");
+
+	igt_subtest(test_name) {
+		/* try to light all pipes */
+		igt_display_all_on(display);
+
+		igt_dir_explorer_read_and_discard_all(debugfs, 0);
+	}
+
+	snprintf(test_name, sizeof(test_name),
+		 "debugfs-read-all-entries-display-off");
+
+	igt_subtest(test_name) {
+		igt_display_all_off(display);
+
+		igt_dir_explorer_read_and_discard_all(debugfs, 0);
+	}
+
+	igt_fixture
+		igt_display_fini(display);
+}
+
+IGT_TEST_DESCRIPTION("Read entries from debugfs with display on/off.");
+
+igt_main
+{
+	int debugfs = -1;
+	int fd = -1;
+
+	igt_fixture {
+		fd = drm_open_driver_master(DRIVER_ANY);
+		debugfs = igt_debugfs_dir(fd);
+		igt_require(debugfs >= 0);
+
+		kmstest_set_vt_graphics_mode();
+	}
+
+	igt_subtest_group
+		kms_tests(fd, debugfs);
+
+	igt_fixture {
+		close(debugfs);
+		drm_close_driver(fd);
+	}
+}
diff --git a/tests/meson.build b/tests/meson.build
index 335d82e9d..c7a689ab3 100644
--- a/tests/meson.build
+++ b/tests/meson.build
@@ -1,5 +1,7 @@
 test_progs = [
 	'core_auth',
+	'core_debugfs',
+	'core_debugfs_display_on_off',
 	'core_getclient',
 	'core_getstats',
 	'core_getversion',
-- 
2.43.0