diff --git a/drivers/gpu/drm/tests/Makefile b/drivers/gpu/drm/tests/Makefile
index 56dab563abd7a7ee7c147bd6b4927e2436b82e1d..0109bcf7faa54993cce337f522eae78f0fa6ffcb 100644
--- a/drivers/gpu/drm/tests/Makefile
+++ b/drivers/gpu/drm/tests/Makefile
@@ -4,6 +4,7 @@ obj-$(CONFIG_DRM_KUNIT_TEST_HELPERS) += \
 	drm_kunit_helpers.o
 
 obj-$(CONFIG_DRM_KUNIT_TEST) += \
+	drm_atomic_state_test.o \
 	drm_buddy_test.o \
 	drm_cmdline_parser_test.o \
 	drm_connector_test.o \
diff --git a/drivers/gpu/drm/tests/drm_atomic_state_test.c b/drivers/gpu/drm/tests/drm_atomic_state_test.c
new file mode 100644
index 0000000000000000000000000000000000000000..be1f780249450ead7fbfd19ea98c96b442a94478
--- /dev/null
+++ b/drivers/gpu/drm/tests/drm_atomic_state_test.c
@@ -0,0 +1,244 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Test cases for the drm_atomic_state helpers
+ *
+ * Copyright (c) 2024 Qualcomm Innovation Center, Inc. All rights reserved.
+ */
+
+#include <drm/drm_atomic.h>
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_atomic_uapi.h>
+#include <drm/drm_kunit_helpers.h>
+#include <drm/drm_probe_helper.h>
+
+#define DRM_TEST_ENC_0 BIT(0)
+#define DRM_TEST_ENC_1 BIT(1)
+#define DRM_TEST_ENC_2 BIT(2)
+
+#define DRM_TEST_CONN_0 BIT(0)
+
+static const struct drm_display_mode drm_atomic_test_mode = {
+	DRM_MODE("1024x768", 0, 65000, 1024, 1048,
+		 1184, 1344, 0, 768, 771, 777, 806, 0,
+		 DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC)
+};
+
+struct drm_atomic_test_priv {
+	struct drm_device drm;
+	struct drm_plane *plane;
+	struct drm_crtc *crtc;
+	struct drm_encoder encoders[3];
+	struct drm_connector connectors[2];
+};
+
+static int modeset_counter;
+
+static void drm_test_encoder_mode_set(struct drm_encoder *encoder,
+				      struct drm_crtc_state *crtc_state,
+				      struct drm_connector_state *conn_state)
+{
+	modeset_counter++;
+}
+
+static const struct drm_encoder_helper_funcs drm_atomic_test_encoder_funcs = {
+	.atomic_mode_set	= drm_test_encoder_mode_set,
+};
+
+static const struct drm_connector_funcs dummy_connector_funcs = {
+	.atomic_destroy_state	= drm_atomic_helper_connector_destroy_state,
+	.atomic_duplicate_state	= drm_atomic_helper_connector_duplicate_state,
+	.reset			= drm_atomic_helper_connector_reset,
+};
+
+static int drm_atomic_test_dummy_get_modes(struct drm_connector *connector)
+{
+	return drm_connector_helper_get_modes_fixed(connector,
+						    &drm_atomic_test_mode);
+}
+
+static const struct drm_connector_helper_funcs dummy_connector_helper_funcs = {
+	.get_modes	= drm_atomic_test_dummy_get_modes,
+};
+
+static struct drm_atomic_test_priv *
+drm_atomic_test_init_drm_components(struct kunit *test, bool has_connectors)
+{
+	struct drm_atomic_test_priv *priv;
+	struct drm_encoder *enc;
+	struct drm_connector *conn;
+	struct drm_device *drm;
+	struct device *dev;
+	int ret;
+
+	dev = drm_kunit_helper_alloc_device(test);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, dev);
+
+	priv = drm_kunit_helper_alloc_drm_device(test, dev,
+						 struct drm_atomic_test_priv,
+						 drm,
+						 DRIVER_MODESET | DRIVER_ATOMIC);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, priv);
+	test->priv = priv;
+
+	drm = &priv->drm;
+	priv->plane = drm_kunit_helper_create_primary_plane(test, drm,
+							    NULL,
+							    NULL,
+							    NULL, 0,
+							    NULL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, priv->plane);
+
+	priv->crtc = drm_kunit_helper_create_crtc(test, drm,
+						  priv->plane, NULL,
+						  NULL,
+						  NULL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, priv->crtc);
+
+	for (int i = 0; i < ARRAY_SIZE(priv->encoders); i++) {
+		enc = &priv->encoders[i];
+
+		ret = drmm_encoder_init(drm, enc, NULL,
+					DRM_MODE_ENCODER_DSI, NULL);
+		KUNIT_ASSERT_EQ(test, ret, 0);
+
+		enc->possible_crtcs = drm_crtc_mask(priv->crtc);
+	}
+
+	priv->encoders[0].possible_clones = DRM_TEST_ENC_0 | DRM_TEST_ENC_1;
+	priv->encoders[1].possible_clones = DRM_TEST_ENC_0 | DRM_TEST_ENC_1;
+	priv->encoders[2].possible_clones = DRM_TEST_ENC_2;
+
+	if (!has_connectors)
+		goto done;
+
+	BUILD_BUG_ON(ARRAY_SIZE(priv->connectors) > ARRAY_SIZE(priv->encoders));
+
+	for (int i = 0; i < ARRAY_SIZE(priv->connectors); i++) {
+		conn = &priv->connectors[i];
+
+		ret = drmm_connector_init(drm, conn, &dummy_connector_funcs,
+					  DRM_MODE_CONNECTOR_DSI, NULL);
+		KUNIT_ASSERT_EQ(test, ret, 0);
+
+		drm_connector_helper_add(conn, &dummy_connector_helper_funcs);
+		drm_encoder_helper_add(&priv->encoders[i],
+				       &drm_atomic_test_encoder_funcs);
+
+		drm_connector_attach_encoder(conn, &priv->encoders[i]);
+	}
+
+done:
+	drm_mode_config_reset(drm);
+
+	return priv;
+}
+
+static int set_up_atomic_state(struct kunit *test,
+			       struct drm_atomic_test_priv *priv,
+			       struct drm_connector *connector,
+			       struct drm_modeset_acquire_ctx *ctx)
+{
+	struct drm_device *drm = &priv->drm;
+	struct drm_crtc *crtc = priv->crtc;
+	struct drm_atomic_state *state;
+	struct drm_connector_state *conn_state;
+	struct drm_crtc_state *crtc_state;
+	int ret;
+
+	state = drm_kunit_helper_atomic_state_alloc(test, drm, ctx);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, state);
+
+	if (connector) {
+		conn_state = drm_atomic_get_connector_state(state, connector);
+		KUNIT_ASSERT_NOT_ERR_OR_NULL(test, conn_state);
+
+		ret = drm_atomic_set_crtc_for_connector(conn_state, crtc);
+		KUNIT_EXPECT_EQ(test, ret, 0);
+	}
+
+	crtc_state = drm_atomic_get_crtc_state(state, crtc);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, crtc_state);
+
+	ret = drm_atomic_set_mode_for_crtc(crtc_state, &drm_atomic_test_mode);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+
+	crtc_state->enable = true;
+	crtc_state->active = true;
+
+	if (connector) {
+		ret = drm_atomic_commit(state);
+		KUNIT_ASSERT_EQ(test, ret, 0);
+	} else {
+		// dummy connector mask
+		crtc_state->connector_mask = DRM_TEST_CONN_0;
+	}
+
+	return 0;
+}
+
+/*
+ * Test that the DRM encoder mode_set() is called when the atomic state
+ * connectors are changed but the CRTC mode is not.
+ */
+static void drm_test_check_connector_changed_modeset(struct kunit *test)
+{
+	struct drm_atomic_test_priv *priv;
+	struct drm_modeset_acquire_ctx *ctx;
+	struct drm_connector *old_conn, *new_conn;
+	struct drm_atomic_state *state;
+	struct drm_device *drm;
+	struct drm_connector_state *new_conn_state, *old_conn_state;
+	int ret, initial_modeset_count;
+
+	priv = drm_atomic_test_init_drm_components(test, true);
+	KUNIT_ASSERT_NOT_NULL(test, priv);
+
+	drm = &priv->drm;
+	old_conn = &priv->connectors[0];
+	new_conn = &priv->connectors[1];
+
+	ctx = drm_kunit_helper_acquire_ctx_alloc(test);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ctx);
+
+	// first modeset to enable
+	ret = set_up_atomic_state(test, priv, old_conn, ctx);
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	state = drm_kunit_helper_atomic_state_alloc(test, drm, ctx);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, state);
+
+	new_conn_state = drm_atomic_get_connector_state(state, new_conn);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, new_conn_state);
+
+	old_conn_state = drm_atomic_get_connector_state(state, old_conn);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, old_conn_state);
+
+	ret = drm_atomic_set_crtc_for_connector(old_conn_state, NULL);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+
+	ret = drm_atomic_set_crtc_for_connector(new_conn_state, priv->crtc);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+
+	initial_modeset_count = modeset_counter;
+
+	// modeset_disables is called as part of the atomic commit tail
+	ret = drm_atomic_commit(state);
+	KUNIT_ASSERT_EQ(test, ret, 0);
+	KUNIT_ASSERT_EQ(test, modeset_counter, initial_modeset_count + 1);
+}
+
+static struct kunit_case drm_test_check_modeset_test[] = {
+	KUNIT_CASE(drm_test_check_connector_changed_modeset),
+	{}
+};
+
+static struct kunit_suite drm_test_check_modeset_test_suite = {
+	.name = "drm_validate_modeset",
+	.test_cases = drm_test_check_modeset_test,
+};
+
+kunit_test_suite(drm_test_check_modeset_test_suite);
+
+MODULE_AUTHOR("Jessica Zhang <quic_jesszhan@quicinc.com");
+MODULE_DESCRIPTION("Test cases for the drm_atomic_helper functions");
+MODULE_LICENSE("GPL");
