drm/amd/display: Try RGB before YCbCr 4:4:4 in stream validationgrafted

amdgpu_dm_create_validate_stream_for_sink() walks encoding_order[] and
uses the first encoding that validates. YCbCr 4:4:4 is listed before
RGB, so an HDMI sink that advertises 4:4:4 gets YCbCr 4:4:4 whenever the
"color format" property is left at AUTO, even though RGB fits the same
link.

That contradicts the documented AUTO behaviour for HDMI in enum
drm_connector_color_format (RGB, falling back to YCbCr 4:2:0 only when
the bandwidth is not available or the mode is 4:2:0-only), which the
amdgpu implementation of the property also describes. It also leaves
the "Broadcast RGB" property without effect on such sinks, since the
quantization range it selects only applies to RGB output.

Try RGB first. The mask still holds every encoding the sink supports,
so a mode that cannot carry RGB falls back exactly as before.

For reference, v7.2 picked RGB here unless YCbCr 4:4:4 was forced
through debugfs, while earlier kernels picked YCbCr 4:4:4 for any HDMI
sink that advertised it.

Fixes: 0b0ff65d3ca1 ("drm/amd/display: Refactor stream validation")
Suggested-by: Adolfo Rodrigues <adolfotregosa@gmail.com>
Assisted-by: Claude Code:claude-fable-5-1
Signed-off-by: Adrian Betschart <adrian.betschart@cinemaone.ch>
Reviewed-by: Fangzhi Zuo <jerry.zuo@amd.com>
Tested-by: Adolfo Rodrigues <adolfotregosa@gmail.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit 7de432bc753133764dc40d37f9388da56de251e7)

1 files changed, 652 insertions, 0 deletions

diff --git a/drivers/base/test/property-entry-test.c b/drivers/base/test/property-entry-test.c
new file mode 100644
index 000000000..89cdfc2f8
--- /dev/null
+++ b/drivers/base/test/property-entry-test.c
@@ -0,0 +1,652 @@
+// SPDX-License-Identifier: GPL-2.0
+// Unit tests for property entries API
+//
+// Copyright 2019 Google LLC.
+
+#include <kunit/test.h>
+
+#include <linux/of.h>
+#include <linux/property.h>
+#include <linux/types.h>
+
+static void pe_test_uints(struct kunit *test)
+{
+	static const struct property_entry entries[] = {
+		PROPERTY_ENTRY_U8("prop-u8", 8),
+		PROPERTY_ENTRY_U16("prop-u16", 16),
+		PROPERTY_ENTRY_U32("prop-u32", 32),
+		PROPERTY_ENTRY_U64("prop-u64", 64),
+		{ }
+	};
+
+	struct fwnode_handle *node;
+	u8 val_u8, array_u8[2];
+	u16 val_u16, array_u16[2];
+	u32 val_u32, array_u32[2];
+	u64 val_u64, array_u64[2];
+	int error;
+
+	node = fwnode_create_software_node(entries, NULL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, node);
+
+	error = fwnode_property_count_u8(node, "prop-u8");
+	KUNIT_EXPECT_EQ(test, error, 1);
+
+	error = fwnode_property_read_u8(node, "prop-u8", &val_u8);
+	KUNIT_EXPECT_EQ(test, error, 0);
+	KUNIT_EXPECT_EQ(test, val_u8, 8);
+
+	error = fwnode_property_read_u8_array(node, "prop-u8", array_u8, 1);
+	KUNIT_EXPECT_EQ(test, error, 0);
+	KUNIT_EXPECT_EQ(test, array_u8[0], 8);
+
+	error = fwnode_property_read_u8_array(node, "prop-u8", array_u8, 2);
+	KUNIT_EXPECT_NE(test, error, 0);
+
+	error = fwnode_property_read_u8(node, "no-prop-u8", &val_u8);
+	KUNIT_EXPECT_NE(test, error, 0);
+
+	error = fwnode_property_read_u8_array(node, "no-prop-u8", array_u8, 1);
+	KUNIT_EXPECT_NE(test, error, 0);
+
+	error = fwnode_property_read_u16(node, "prop-u16", &val_u16);
+	KUNIT_EXPECT_EQ(test, error, 0);
+	KUNIT_EXPECT_EQ(test, val_u16, 16);
+
+	error = fwnode_property_count_u16(node, "prop-u16");
+	KUNIT_EXPECT_EQ(test, error, 1);
+
+	error = fwnode_property_read_u16_array(node, "prop-u16", array_u16, 1);
+	KUNIT_EXPECT_EQ(test, error, 0);
+	KUNIT_EXPECT_EQ(test, array_u16[0], 16);
+
+	error = fwnode_property_read_u16_array(node, "prop-u16", array_u16, 2);
+	KUNIT_EXPECT_NE(test, error, 0);
+
+	error = fwnode_property_read_u16(node, "no-prop-u16", &val_u16);
+	KUNIT_EXPECT_NE(test, error, 0);
+
+	error = fwnode_property_read_u16_array(node, "no-prop-u16", array_u16, 1);
+	KUNIT_EXPECT_NE(test, error, 0);
+
+	error = fwnode_property_read_u32(node, "prop-u32", &val_u32);
+	KUNIT_EXPECT_EQ(test, error, 0);
+	KUNIT_EXPECT_EQ(test, val_u32, 32);
+
+	error = fwnode_property_count_u32(node, "prop-u32");
+	KUNIT_EXPECT_EQ(test, error, 1);
+
+	error = fwnode_property_read_u32_array(node, "prop-u32", array_u32, 1);
+	KUNIT_EXPECT_EQ(test, error, 0);
+	KUNIT_EXPECT_EQ(test, array_u32[0], 32);
+
+	error = fwnode_property_read_u32_array(node, "prop-u32", array_u32, 2);
+	KUNIT_EXPECT_NE(test, error, 0);
+
+	error = fwnode_property_read_u32(node, "no-prop-u32", &val_u32);
+	KUNIT_EXPECT_NE(test, error, 0);
+
+	error = fwnode_property_read_u32_array(node, "no-prop-u32", array_u32, 1);
+	KUNIT_EXPECT_NE(test, error, 0);
+
+	error = fwnode_property_read_u64(node, "prop-u64", &val_u64);
+	KUNIT_EXPECT_EQ(test, error, 0);
+	KUNIT_EXPECT_EQ(test, val_u64, 64);
+
+	error = fwnode_property_count_u64(node, "prop-u64");
+	KUNIT_EXPECT_EQ(test, error, 1);
+
+	error = fwnode_property_read_u64_array(node, "prop-u64", array_u64, 1);
+	KUNIT_EXPECT_EQ(test, error, 0);
+	KUNIT_EXPECT_EQ(test, array_u64[0], 64);
+
+	error = fwnode_property_read_u64_array(node, "prop-u64", array_u64, 2);
+	KUNIT_EXPECT_NE(test, error, 0);
+
+	error = fwnode_property_read_u64(node, "no-prop-u64", &val_u64);
+	KUNIT_EXPECT_NE(test, error, 0);
+
+	error = fwnode_property_read_u64_array(node, "no-prop-u64", array_u64, 1);
+	KUNIT_EXPECT_NE(test, error, 0);
+
+	/* Count 64-bit values as 16-bit */
+	error = fwnode_property_count_u16(node, "prop-u64");
+	KUNIT_EXPECT_EQ(test, error, 4);
+
+	fwnode_remove_software_node(node);
+}
+
+static void pe_test_uint_arrays(struct kunit *test)
+{
+	static const u8 a_u8[10] = { 8, 9 };
+	static const u16 a_u16[10] = { 16, 17 };
+	static const u32 a_u32[10] = { 32, 33 };
+	static const u64 a_u64[10] = { 64, 65 };
+	static const struct property_entry entries[] = {
+		PROPERTY_ENTRY_U8_ARRAY("prop-u8", a_u8),
+		PROPERTY_ENTRY_U16_ARRAY("prop-u16", a_u16),
+		PROPERTY_ENTRY_U32_ARRAY("prop-u32", a_u32),
+		PROPERTY_ENTRY_U64_ARRAY("prop-u64", a_u64),
+		{ }
+	};
+
+	struct fwnode_handle *node;
+	u8 val_u8, array_u8[32];
+	u16 val_u16, array_u16[32];
+	u32 val_u32, array_u32[32];
+	u64 val_u64, array_u64[32];
+	int error;
+
+	node = fwnode_create_software_node(entries, NULL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, node);
+
+	error = fwnode_property_read_u8(node, "prop-u8", &val_u8);
+	KUNIT_EXPECT_EQ(test, error, 0);
+	KUNIT_EXPECT_EQ(test, val_u8, 8);
+
+	error = fwnode_property_count_u8(node, "prop-u8");
+	KUNIT_EXPECT_EQ(test, error, 10);
+
+	error = fwnode_property_read_u8_array(node, "prop-u8", array_u8, 1);
+	KUNIT_EXPECT_EQ(test, error, 0);
+	KUNIT_EXPECT_EQ(test, array_u8[0], 8);
+
+	error = fwnode_property_read_u8_array(node, "prop-u8", array_u8, 2);
+	KUNIT_EXPECT_EQ(test, error, 0);
+	KUNIT_EXPECT_EQ(test, array_u8[0], 8);
+	KUNIT_EXPECT_EQ(test, array_u8[1], 9);
+
+	error = fwnode_property_read_u8_array(node, "prop-u8", array_u8, 17);
+	KUNIT_EXPECT_NE(test, error, 0);
+
+	error = fwnode_property_read_u8(node, "no-prop-u8", &val_u8);
+	KUNIT_EXPECT_NE(test, error, 0);
+
+	error = fwnode_property_read_u8_array(node, "no-prop-u8", array_u8, 1);
+	KUNIT_EXPECT_NE(test, error, 0);
+
+	error = fwnode_property_read_u16(node, "prop-u16", &val_u16);
+	KUNIT_EXPECT_EQ(test, error, 0);
+	KUNIT_EXPECT_EQ(test, val_u16, 16);
+
+	error = fwnode_property_count_u16(node, "prop-u16");
+	KUNIT_EXPECT_EQ(test, error, 10);
+
+	error = fwnode_property_read_u16_array(node, "prop-u16", array_u16, 1);
+	KUNIT_EXPECT_EQ(test, error, 0);
+	KUNIT_EXPECT_EQ(test, array_u16[0], 16);
+
+	error = fwnode_property_read_u16_array(node, "prop-u16", array_u16, 2);
+	KUNIT_EXPECT_EQ(test, error, 0);
+	KUNIT_EXPECT_EQ(test, array_u16[0], 16);
+	KUNIT_EXPECT_EQ(test, array_u16[1], 17);
+
+	error = fwnode_property_read_u16_array(node, "prop-u16", array_u16, 17);
+	KUNIT_EXPECT_NE(test, error, 0);
+
+	error = fwnode_property_read_u16(node, "no-prop-u16", &val_u16);
+	KUNIT_EXPECT_NE(test, error, 0);
+
+	error = fwnode_property_read_u16_array(node, "no-prop-u16", array_u16, 1);
+	KUNIT_EXPECT_NE(test, error, 0);
+
+	error = fwnode_property_read_u32(node, "prop-u32", &val_u32);
+	KUNIT_EXPECT_EQ(test, error, 0);
+	KUNIT_EXPECT_EQ(test, val_u32, 32);
+
+	error = fwnode_property_count_u32(node, "prop-u32");
+	KUNIT_EXPECT_EQ(test, error, 10);
+
+	error = fwnode_property_read_u32_array(node, "prop-u32", array_u32, 1);
+	KUNIT_EXPECT_EQ(test, error, 0);
+	KUNIT_EXPECT_EQ(test, array_u32[0], 32);
+
+	error = fwnode_property_read_u32_array(node, "prop-u32", array_u32, 2);
+	KUNIT_EXPECT_EQ(test, error, 0);
+	KUNIT_EXPECT_EQ(test, array_u32[0], 32);
+	KUNIT_EXPECT_EQ(test, array_u32[1], 33);
+
+	error = fwnode_property_read_u32_array(node, "prop-u32", array_u32, 17);
+	KUNIT_EXPECT_NE(test, error, 0);
+
+	error = fwnode_property_read_u32(node, "no-prop-u32", &val_u32);
+	KUNIT_EXPECT_NE(test, error, 0);
+
+	error = fwnode_property_read_u32_array(node, "no-prop-u32", array_u32, 1);
+	KUNIT_EXPECT_NE(test, error, 0);
+
+	error = fwnode_property_read_u64(node, "prop-u64", &val_u64);
+	KUNIT_EXPECT_EQ(test, error, 0);
+	KUNIT_EXPECT_EQ(test, val_u64, 64);
+
+	error = fwnode_property_count_u64(node, "prop-u64");
+	KUNIT_EXPECT_EQ(test, error, 10);
+
+	error = fwnode_property_read_u64_array(node, "prop-u64", array_u64, 1);
+	KUNIT_EXPECT_EQ(test, error, 0);
+	KUNIT_EXPECT_EQ(test, array_u64[0], 64);
+
+	error = fwnode_property_read_u64_array(node, "prop-u64", array_u64, 2);
+	KUNIT_EXPECT_EQ(test, error, 0);
+	KUNIT_EXPECT_EQ(test, array_u64[0], 64);
+	KUNIT_EXPECT_EQ(test, array_u64[1], 65);
+
+	error = fwnode_property_read_u64_array(node, "prop-u64", array_u64, 17);
+	KUNIT_EXPECT_NE(test, error, 0);
+
+	error = fwnode_property_read_u64(node, "no-prop-u64", &val_u64);
+	KUNIT_EXPECT_NE(test, error, 0);
+
+	error = fwnode_property_read_u64_array(node, "no-prop-u64", array_u64, 1);
+	KUNIT_EXPECT_NE(test, error, 0);
+
+	/* Count 64-bit values as 16-bit */
+	error = fwnode_property_count_u16(node, "prop-u64");
+	KUNIT_EXPECT_EQ(test, error, 40);
+
+	/* Other way around */
+	error = fwnode_property_count_u64(node, "prop-u16");
+	KUNIT_EXPECT_EQ(test, error, 2);
+
+	fwnode_remove_software_node(node);
+}
+
+static void pe_test_strings(struct kunit *test)
+{
+	static const char *strings[] = {
+		"string-a",
+		"string-b",
+	};
+
+	static const struct property_entry entries[] = {
+		PROPERTY_ENTRY_STRING("str", "single"),
+		PROPERTY_ENTRY_STRING("empty", ""),
+		PROPERTY_ENTRY_STRING_ARRAY("strs", strings),
+		{ }
+	};
+
+	struct fwnode_handle *node;
+	const char *str;
+	const char *strs[10];
+	int error;
+
+	node = fwnode_create_software_node(entries, NULL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, node);
+
+	error = fwnode_property_read_string(node, "str", &str);
+	KUNIT_EXPECT_EQ(test, error, 0);
+	KUNIT_EXPECT_STREQ(test, str, "single");
+
+	error = fwnode_property_string_array_count(node, "str");
+	KUNIT_EXPECT_EQ(test, error, 1);
+
+	error = fwnode_property_read_string_array(node, "str", strs, 1);
+	KUNIT_EXPECT_EQ(test, error, 1);
+	KUNIT_EXPECT_STREQ(test, strs[0], "single");
+
+	/* asking for more data returns what we have */
+	error = fwnode_property_read_string_array(node, "str", strs, 2);
+	KUNIT_EXPECT_EQ(test, error, 1);
+	KUNIT_EXPECT_STREQ(test, strs[0], "single");
+
+	error = fwnode_property_read_string(node, "no-str", &str);
+	KUNIT_EXPECT_NE(test, error, 0);
+
+	error = fwnode_property_read_string_array(node, "no-str", strs, 1);
+	KUNIT_EXPECT_LT(test, error, 0);
+
+	error = fwnode_property_read_string(node, "empty", &str);
+	KUNIT_EXPECT_EQ(test, error, 0);
+	KUNIT_EXPECT_STREQ(test, str, "");
+
+	error = fwnode_property_string_array_count(node, "strs");
+	KUNIT_EXPECT_EQ(test, error, 2);
+
+	error = fwnode_property_read_string_array(node, "strs", strs, 3);
+	KUNIT_EXPECT_EQ(test, error, 2);
+	KUNIT_EXPECT_STREQ(test, strs[0], "string-a");
+	KUNIT_EXPECT_STREQ(test, strs[1], "string-b");
+
+	error = fwnode_property_read_string_array(node, "strs", strs, 1);
+	KUNIT_EXPECT_EQ(test, error, 1);
+	KUNIT_EXPECT_STREQ(test, strs[0], "string-a");
+
+	/* NULL argument -> returns size */
+	error = fwnode_property_read_string_array(node, "strs", NULL, 0);
+	KUNIT_EXPECT_EQ(test, error, 2);
+
+	/* accessing array as single value */
+	error = fwnode_property_read_string(node, "strs", &str);
+	KUNIT_EXPECT_EQ(test, error, 0);
+	KUNIT_EXPECT_STREQ(test, str, "string-a");
+
+	fwnode_remove_software_node(node);
+}
+
+static void pe_test_bool(struct kunit *test)
+{
+	static const struct property_entry entries[] = {
+		PROPERTY_ENTRY_BOOL("prop"),
+		{ }
+	};
+
+	struct fwnode_handle *node;
+
+	node = fwnode_create_software_node(entries, NULL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, node);
+
+	KUNIT_EXPECT_TRUE(test, fwnode_property_read_bool(node, "prop"));
+	KUNIT_EXPECT_FALSE(test, fwnode_property_read_bool(node, "not-prop"));
+
+	fwnode_remove_software_node(node);
+}
+
+/* Verifies that small U8 array is stored inline when property is copied */
+static void pe_test_move_inline_u8(struct kunit *test)
+{
+	static const u8 u8_array_small[8] = { 1, 2, 3, 4 };
+	static const u8 u8_array_big[128] = { 5, 6, 7, 8 };
+	static const struct property_entry entries[] = {
+		PROPERTY_ENTRY_U8_ARRAY("small", u8_array_small),
+		PROPERTY_ENTRY_U8_ARRAY("big", u8_array_big),
+		{ }
+	};
+
+	struct property_entry *copy;
+	const u8 *data_ptr;
+
+	copy = property_entries_dup(entries);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, copy);
+
+	KUNIT_EXPECT_TRUE(test, copy[0].is_inline);
+	data_ptr = (u8 *)&copy[0].value;
+	KUNIT_EXPECT_EQ(test, data_ptr[0], 1);
+	KUNIT_EXPECT_EQ(test, data_ptr[1], 2);
+
+	KUNIT_EXPECT_FALSE(test, copy[1].is_inline);
+	data_ptr = copy[1].pointer;
+	KUNIT_EXPECT_EQ(test, data_ptr[0], 5);
+	KUNIT_EXPECT_EQ(test, data_ptr[1], 6);
+
+	property_entries_free(copy);
+}
+
+/* Verifies that single string array is stored inline when property is copied */
+static void pe_test_move_inline_str(struct kunit *test)
+{
+	static char *str_array_small[] = { "a" };
+	static char *str_array_big[] = { "b", "c", "d", "e" };
+	static char *str_array_small_empty[] = { "" };
+	static struct property_entry entries[] = {
+		PROPERTY_ENTRY_STRING_ARRAY("small", str_array_small),
+		PROPERTY_ENTRY_STRING_ARRAY("big", str_array_big),
+		PROPERTY_ENTRY_STRING_ARRAY("small-empty", str_array_small_empty),
+		{ }
+	};
+
+	struct property_entry *copy;
+	const char * const *data_ptr;
+
+	copy = property_entries_dup(entries);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, copy);
+
+	KUNIT_EXPECT_TRUE(test, copy[0].is_inline);
+	KUNIT_EXPECT_STREQ(test, copy[0].value.str[0], "a");
+
+	KUNIT_EXPECT_FALSE(test, copy[1].is_inline);
+	data_ptr = copy[1].pointer;
+	KUNIT_EXPECT_STREQ(test, data_ptr[0], "b");
+	KUNIT_EXPECT_STREQ(test, data_ptr[1], "c");
+
+	KUNIT_EXPECT_TRUE(test, copy[2].is_inline);
+	KUNIT_EXPECT_STREQ(test, copy[2].value.str[0], "");
+
+	property_entries_free(copy);
+}
+
+/* Handling of reference properties */
+static void pe_test_reference(struct kunit *test)
+{
+	static const struct software_node node1 = { .name = "1" };
+	static const struct software_node node2 = { .name = "2" };
+	static const struct software_node *group[] = { &node1, &node2, NULL };
+
+	static const struct software_node_ref_args refs[] = {
+		SOFTWARE_NODE_REFERENCE(&node1),
+		SOFTWARE_NODE_REFERENCE(&node2, 3, 4),
+	};
+
+	const struct property_entry entries[] = {
+		PROPERTY_ENTRY_REF("ref-1", &node1),
+		PROPERTY_ENTRY_REF("ref-2", &node2, 1, 2),
+		PROPERTY_ENTRY_REF_ARRAY("ref-3", refs),
+		{ }
+	};
+
+	struct fwnode_handle *node;
+	struct fwnode_reference_args ref;
+	int error;
+
+	error = software_node_register_node_group(group);
+	KUNIT_ASSERT_EQ(test, error, 0);
+
+	node = fwnode_create_software_node(entries, NULL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, node);
+
+	error = fwnode_property_get_reference_args(node, "ref-1", NULL,
+						   0, 0, &ref);
+	KUNIT_ASSERT_EQ(test, error, 0);
+	KUNIT_EXPECT_PTR_EQ(test, to_software_node(ref.fwnode), &node1);
+	KUNIT_EXPECT_EQ(test, ref.nargs, 0U);
+
+	/* wrong index */
+	error = fwnode_property_get_reference_args(node, "ref-1", NULL,
+						   0, 1, &ref);
+	KUNIT_EXPECT_NE(test, error, 0);
+
+	error = fwnode_property_get_reference_args(node, "ref-2", NULL,
+						   1, 0, &ref);
+	KUNIT_ASSERT_EQ(test, error, 0);
+	KUNIT_EXPECT_PTR_EQ(test, to_software_node(ref.fwnode), &node2);
+	KUNIT_EXPECT_EQ(test, ref.nargs, 1U);
+	KUNIT_EXPECT_EQ(test, ref.args[0], 1LLU);
+
+	/* asking for more args, padded with zero data */
+	error = fwnode_property_get_reference_args(node, "ref-2", NULL,
+						   3, 0, &ref);
+	KUNIT_ASSERT_EQ(test, error, 0);
+	KUNIT_EXPECT_PTR_EQ(test, to_software_node(ref.fwnode), &node2);
+	KUNIT_EXPECT_EQ(test, ref.nargs, 3U);
+	KUNIT_EXPECT_EQ(test, ref.args[0], 1LLU);
+	KUNIT_EXPECT_EQ(test, ref.args[1], 2LLU);
+	KUNIT_EXPECT_EQ(test, ref.args[2], 0LLU);
+
+	/* wrong index */
+	error = fwnode_property_get_reference_args(node, "ref-2", NULL,
+						   2, 1, &ref);
+	KUNIT_EXPECT_NE(test, error, 0);
+
+	/* array of references */
+	error = fwnode_property_get_reference_args(node, "ref-3", NULL,
+						   0, 0, &ref);
+	KUNIT_ASSERT_EQ(test, error, 0);
+	KUNIT_EXPECT_PTR_EQ(test, to_software_node(ref.fwnode), &node1);
+	KUNIT_EXPECT_EQ(test, ref.nargs, 0U);
+
+	/* second reference in the array */
+	error = fwnode_property_get_reference_args(node, "ref-3", NULL,
+						   2, 1, &ref);
+	KUNIT_ASSERT_EQ(test, error, 0);
+	KUNIT_EXPECT_PTR_EQ(test, to_software_node(ref.fwnode), &node2);
+	KUNIT_EXPECT_EQ(test, ref.nargs, 2U);
+	KUNIT_EXPECT_EQ(test, ref.args[0], 3LLU);
+	KUNIT_EXPECT_EQ(test, ref.args[1], 4LLU);
+
+	/* wrong index */
+	error = fwnode_property_get_reference_args(node, "ref-1", NULL,
+						   0, 2, &ref);
+	KUNIT_EXPECT_NE(test, error, 0);
+
+	fwnode_remove_software_node(node);
+	software_node_unregister_node_group(group);
+}
+
+static struct fwnode_handle *create_device_node(struct kunit *test,
+						const char *name,
+						const char *full_name,
+						struct device_node *parent)
+{
+	struct device_node *node;
+
+	node = kunit_kzalloc(test, sizeof(*node), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, node);
+
+	node->name = kunit_kstrdup(test, name, GFP_KERNEL);
+	node->full_name = kunit_kstrdup(test, full_name, GFP_KERNEL);
+
+	if (parent) {
+		node->sibling = parent->child;
+		/* set the node as the first child of the parent */
+		parent->child = node;
+		node->parent = parent;
+	}
+
+	of_node_init(node);
+	return of_fwnode_handle(node);
+}
+
+/* Verifies that fwnode_for_each_child_node() can output correct children */
+static void pe_test_child_iteration(struct kunit *test)
+{
+	struct fwnode_handle *of_node, *of_node1;
+	struct fwnode_handle *sw_node, *sw_node1;
+	struct fwnode_handle *child;
+	int error, i, num;
+
+	if (!IS_ENABLED(CONFIG_OF))
+		kunit_skip(test, "requires CONFIG_OF");
+
+	static const struct software_node node = { .name = "sw" };
+	static const struct software_node node1 = { .name = "sw-1", .parent = &node};
+	static const struct software_node node2 = { .name = "sw-2", .parent = &node};
+	static const struct software_node node3 = { .name = "sw-3", .parent = &node};
+	static const struct software_node *group[] = { &node, &node1, &node2, &node3, NULL };
+
+	static const char * const of_child_array[] = { "of-1", "of-2", "of-3" };
+	static const char * const sw_child_array[] = { "sw-1", "sw-2", "sw-3" };
+	static const char * const of_sw_child_array[] = { "of-1", "of-2", "of-3",
+							  "sw-1", "sw-2", "sw-3" };
+	static const char * const sw_of_child_array[] = { "sw-1", "sw-2", "sw-3",
+							  "of-1", "of-2", "of-3" };
+
+	/* 1. Test OF node child iteration */
+
+	of_node = create_device_node(test, "of", "of", NULL);
+	create_device_node(test, "of", "of-3", to_of_node(of_node));
+	create_device_node(test, "of", "of-2", to_of_node(of_node));
+	of_node1 = create_device_node(test, "of", "of-1", to_of_node(of_node));
+
+	i = 0;
+	num = ARRAY_SIZE(of_child_array);
+	fwnode_for_each_child_node(of_node, child) {
+		KUNIT_ASSERT_LT(test, i, num);
+		KUNIT_EXPECT_STREQ(test, of_child_array[i++], fwnode_get_name(child));
+	}
+	KUNIT_EXPECT_PTR_EQ(test, child, NULL);
+
+	/* 2. Test SW node child iteration */
+
+	error = software_node_register_node_group(group);
+	KUNIT_ASSERT_EQ(test, error, 0);
+
+	sw_node = software_node_fwnode(&node);
+
+	i = 0;
+	num = ARRAY_SIZE(sw_child_array);
+	fwnode_for_each_child_node(sw_node, child) {
+		KUNIT_ASSERT_LT(test, i, num);
+		KUNIT_EXPECT_STREQ(test, sw_child_array[i++], fwnode_get_name(child));
+	}
+	KUNIT_EXPECT_PTR_EQ(test, child, NULL);
+
+	/* 3. Test OF (primary) + SW (secondary) node child iteration */
+
+	of_node->secondary = sw_node;
+	sw_node->secondary = ERR_PTR(-ENODEV);
+
+	i = 0;
+	num = ARRAY_SIZE(of_sw_child_array);
+	fwnode_for_each_child_node(of_node, child) {
+		KUNIT_ASSERT_LT(test, i, num);
+		KUNIT_EXPECT_STREQ(test, of_sw_child_array[i++], fwnode_get_name(child));
+	}
+	KUNIT_EXPECT_PTR_EQ(test, child, NULL);
+
+	/* 4. Test SW (primary) + OF (secondary) node child iteration */
+
+	sw_node->secondary = of_node;
+	of_node->secondary = ERR_PTR(-ENODEV);
+
+	i = 0;
+	num = ARRAY_SIZE(sw_of_child_array);
+	fwnode_for_each_child_node(sw_node, child) {
+		KUNIT_ASSERT_LT(test, i, num);
+		KUNIT_EXPECT_STREQ(test, sw_of_child_array[i++], fwnode_get_name(child));
+	}
+	KUNIT_EXPECT_PTR_EQ(test, child, NULL);
+
+	/* 5. Test OF (primary) + SW (secondary, but no children) node child iteration */
+
+	sw_node1 = software_node_fwnode(&node1);
+	of_node->secondary = sw_node1;
+	sw_node->secondary = ERR_PTR(-ENODEV);
+
+	i = 0;
+	num = ARRAY_SIZE(of_child_array);
+	fwnode_for_each_child_node(of_node, child) {
+		KUNIT_ASSERT_LT(test, i, num);
+		KUNIT_EXPECT_STREQ(test, of_child_array[i++], fwnode_get_name(child));
+	}
+	KUNIT_EXPECT_PTR_EQ(test, child, NULL);
+
+	/* 6. Test SW (primary) + OF (secondary, but no children) node child iteration */
+
+	sw_node->secondary = of_node1;
+	of_node->secondary = ERR_PTR(-ENODEV);
+
+	i = 0;
+	num = ARRAY_SIZE(sw_child_array);
+	fwnode_for_each_child_node(sw_node, child) {
+		KUNIT_ASSERT_LT(test, i, num);
+		KUNIT_EXPECT_STREQ(test, sw_child_array[i++], fwnode_get_name(child));
+	}
+	KUNIT_EXPECT_PTR_EQ(test, child, NULL);
+
+	of_node->secondary = NULL;
+	sw_node->secondary = NULL;
+	software_node_unregister_node_group(group);
+}
+
+static struct kunit_case property_entry_test_cases[] = {
+	KUNIT_CASE(pe_test_uints),
+	KUNIT_CASE(pe_test_uint_arrays),
+	KUNIT_CASE(pe_test_strings),
+	KUNIT_CASE(pe_test_bool),
+	KUNIT_CASE(pe_test_move_inline_u8),
+	KUNIT_CASE(pe_test_move_inline_str),
+	KUNIT_CASE(pe_test_reference),
+	KUNIT_CASE(pe_test_child_iteration),
+	{ }
+};
+
+static struct kunit_suite property_entry_test_suite = {
+	.name = "property-entry",
+	.test_cases = property_entry_test_cases,
+};
+
+kunit_test_suite(property_entry_test_suite);
+
+MODULE_DESCRIPTION("Test module for the property entry API");
+MODULE_AUTHOR("Dmitry Torokhov <dtor@chromium.org>");
+MODULE_IMPORT_NS("EXPORTED_FOR_KUNIT_TESTING");
+MODULE_LICENSE("GPL");