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, 275 insertions, 0 deletions

diff --git a/lib/kunit/assert.c b/lib/kunit/assert.c
new file mode 100644
index 000000000..4c751ad85
--- /dev/null
+++ b/lib/kunit/assert.c
@@ -0,0 +1,275 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Assertion and expectation serialization API.
+ *
+ * Copyright (C) 2019, Google LLC.
+ * Author: Brendan Higgins <brendanhiggins@google.com>
+ */
+#include <kunit/assert.h>
+#include <kunit/test.h>
+#include <kunit/visibility.h>
+
+#include "string-stream.h"
+
+void kunit_assert_prologue(const struct kunit_loc *loc,
+			   enum kunit_assert_type type,
+			      struct string_stream *stream)
+{
+	const char *expect_or_assert = NULL;
+
+	switch (type) {
+	case KUNIT_EXPECTATION:
+		expect_or_assert = "EXPECTATION";
+		break;
+	case KUNIT_ASSERTION:
+		expect_or_assert = "ASSERTION";
+		break;
+	}
+
+	string_stream_add(stream, "%s FAILED at %s:%d\n",
+			  expect_or_assert, loc->file, loc->line);
+}
+EXPORT_SYMBOL_GPL(kunit_assert_prologue);
+
+VISIBLE_IF_KUNIT
+void kunit_assert_print_msg(const struct va_format *message,
+			    struct string_stream *stream)
+{
+	if (message->fmt)
+		string_stream_add(stream, "\n%pV", message);
+}
+
+void kunit_fail_assert_format(const struct kunit_assert *assert,
+			      const struct va_format *message,
+			      struct string_stream *stream)
+{
+	string_stream_add(stream, "%pV", message);
+}
+EXPORT_SYMBOL_GPL(kunit_fail_assert_format);
+
+void kunit_unary_assert_format(const struct kunit_assert *assert,
+			       const struct va_format *message,
+			       struct string_stream *stream)
+{
+	const struct kunit_unary_assert *unary_assert;
+
+	unary_assert = container_of(assert, struct kunit_unary_assert, assert);
+
+	if (unary_assert->expected_true)
+		string_stream_add(stream,
+				  KUNIT_SUBTEST_INDENT "Expected %s to be true, but is false\n",
+				  unary_assert->condition);
+	else
+		string_stream_add(stream,
+				  KUNIT_SUBTEST_INDENT "Expected %s to be false, but is true\n",
+				  unary_assert->condition);
+	kunit_assert_print_msg(message, stream);
+}
+EXPORT_SYMBOL_GPL(kunit_unary_assert_format);
+
+void kunit_ptr_not_err_assert_format(const struct kunit_assert *assert,
+				     const struct va_format *message,
+				     struct string_stream *stream)
+{
+	const struct kunit_ptr_not_err_assert *ptr_assert;
+
+	ptr_assert = container_of(assert, struct kunit_ptr_not_err_assert,
+				  assert);
+
+	if (!ptr_assert->value) {
+		string_stream_add(stream,
+				  KUNIT_SUBTEST_INDENT "Expected %s is not null, but is\n",
+				  ptr_assert->text);
+	} else if (IS_ERR(ptr_assert->value)) {
+		string_stream_add(stream,
+				  KUNIT_SUBTEST_INDENT "Expected %s is not error, but is: %ld\n",
+				  ptr_assert->text,
+				  PTR_ERR(ptr_assert->value));
+	}
+	kunit_assert_print_msg(message, stream);
+}
+EXPORT_SYMBOL_GPL(kunit_ptr_not_err_assert_format);
+
+/* Checks if `text` is a literal representing `value`, e.g. "5" and 5 */
+VISIBLE_IF_KUNIT bool is_literal(const char *text, long long value)
+{
+	char *buffer;
+	int len;
+	bool ret;
+
+	len = snprintf(NULL, 0, "%lld", value);
+	if (strlen(text) != len)
+		return false;
+
+	buffer = kmalloc(len+1, GFP_KERNEL);
+	if (!buffer)
+		return false;
+
+	snprintf(buffer, len+1, "%lld", value);
+	ret = strncmp(buffer, text, len) == 0;
+
+	kfree(buffer);
+
+	return ret;
+}
+
+void kunit_binary_assert_format(const struct kunit_assert *assert,
+				const struct va_format *message,
+				struct string_stream *stream)
+{
+	const struct kunit_binary_assert *binary_assert;
+
+	binary_assert = container_of(assert, struct kunit_binary_assert,
+				     assert);
+
+	string_stream_add(stream,
+			  KUNIT_SUBTEST_INDENT "Expected %s %s %s, but\n",
+			  binary_assert->text->left_text,
+			  binary_assert->text->operation,
+			  binary_assert->text->right_text);
+	if (!is_literal(binary_assert->text->left_text, binary_assert->left_value))
+		string_stream_add(stream, KUNIT_SUBSUBTEST_INDENT "%s == %lld (0x%llx)\n",
+				  binary_assert->text->left_text,
+				  binary_assert->left_value,
+				  binary_assert->left_value);
+	if (!is_literal(binary_assert->text->right_text, binary_assert->right_value))
+		string_stream_add(stream, KUNIT_SUBSUBTEST_INDENT "%s == %lld (0x%llx)",
+				  binary_assert->text->right_text,
+				  binary_assert->right_value,
+				  binary_assert->right_value);
+	kunit_assert_print_msg(message, stream);
+}
+EXPORT_SYMBOL_GPL(kunit_binary_assert_format);
+
+void kunit_binary_ptr_assert_format(const struct kunit_assert *assert,
+				    const struct va_format *message,
+				    struct string_stream *stream)
+{
+	const struct kunit_binary_ptr_assert *binary_assert;
+
+	binary_assert = container_of(assert, struct kunit_binary_ptr_assert,
+				     assert);
+
+	string_stream_add(stream,
+			  KUNIT_SUBTEST_INDENT "Expected %s %s %s, but\n",
+			  binary_assert->text->left_text,
+			  binary_assert->text->operation,
+			  binary_assert->text->right_text);
+	string_stream_add(stream, KUNIT_SUBSUBTEST_INDENT "%s == %px\n",
+			  binary_assert->text->left_text,
+			  binary_assert->left_value);
+	string_stream_add(stream, KUNIT_SUBSUBTEST_INDENT "%s == %px",
+			  binary_assert->text->right_text,
+			  binary_assert->right_value);
+	kunit_assert_print_msg(message, stream);
+}
+EXPORT_SYMBOL_GPL(kunit_binary_ptr_assert_format);
+
+/* Checks if KUNIT_EXPECT_STREQ() args were string literals.
+ * Note: `text` will have ""s where as `value` will not.
+ */
+VISIBLE_IF_KUNIT bool is_str_literal(const char *text, const char *value)
+{
+	int len;
+
+	len = strlen(text);
+	if (len < 2)
+		return false;
+	if (text[0] != '\"' || text[len - 1] != '\"')
+		return false;
+
+	return strncmp(text + 1, value, len - 2) == 0;
+}
+
+void kunit_binary_str_assert_format(const struct kunit_assert *assert,
+				    const struct va_format *message,
+				    struct string_stream *stream)
+{
+	const struct kunit_binary_str_assert *binary_assert;
+
+	binary_assert = container_of(assert, struct kunit_binary_str_assert,
+				     assert);
+
+	string_stream_add(stream,
+			  KUNIT_SUBTEST_INDENT "Expected %s %s %s, but\n",
+			  binary_assert->text->left_text,
+			  binary_assert->text->operation,
+			  binary_assert->text->right_text);
+	if (!is_str_literal(binary_assert->text->left_text, binary_assert->left_value))
+		string_stream_add(stream, KUNIT_SUBSUBTEST_INDENT "%s == \"%s\"\n",
+				  binary_assert->text->left_text,
+				  binary_assert->left_value);
+	if (!is_str_literal(binary_assert->text->right_text, binary_assert->right_value))
+		string_stream_add(stream, KUNIT_SUBSUBTEST_INDENT "%s == \"%s\"",
+				  binary_assert->text->right_text,
+				  binary_assert->right_value);
+	kunit_assert_print_msg(message, stream);
+}
+EXPORT_SYMBOL_GPL(kunit_binary_str_assert_format);
+
+/* Adds a hexdump of a buffer to a string_stream comparing it with
+ * a second buffer. The different bytes are marked with <>.
+ */
+VISIBLE_IF_KUNIT
+void kunit_assert_hexdump(struct string_stream *stream,
+			  const void *buf,
+			  const void *compared_buf,
+			  const size_t len)
+{
+	size_t i;
+	const u8 *buf1 = buf;
+	const u8 *buf2 = compared_buf;
+
+	string_stream_add(stream, KUNIT_SUBSUBTEST_INDENT);
+
+	for (i = 0; i < len; ++i) {
+		if (!(i % 16) && i)
+			string_stream_add(stream, "\n" KUNIT_SUBSUBTEST_INDENT);
+
+		if (buf1[i] != buf2[i])
+			string_stream_add(stream, "<%02x>", buf1[i]);
+		else
+			string_stream_add(stream, " %02x ", buf1[i]);
+	}
+}
+
+void kunit_mem_assert_format(const struct kunit_assert *assert,
+			     const struct va_format *message,
+			     struct string_stream *stream)
+{
+	const struct kunit_mem_assert *mem_assert;
+
+	mem_assert = container_of(assert, struct kunit_mem_assert,
+				  assert);
+
+	if (!mem_assert->left_value) {
+		string_stream_add(stream,
+				  KUNIT_SUBTEST_INDENT "Expected %s is not null, but is\n",
+				  mem_assert->text->left_text);
+	} else if (!mem_assert->right_value) {
+		string_stream_add(stream,
+				  KUNIT_SUBTEST_INDENT "Expected %s is not null, but is\n",
+				  mem_assert->text->right_text);
+	} else {
+		string_stream_add(stream,
+				KUNIT_SUBTEST_INDENT "Expected %s %s %s, but\n",
+				mem_assert->text->left_text,
+				mem_assert->text->operation,
+				mem_assert->text->right_text);
+
+		string_stream_add(stream, KUNIT_SUBSUBTEST_INDENT "%s ==\n",
+				mem_assert->text->left_text);
+		kunit_assert_hexdump(stream, mem_assert->left_value,
+					mem_assert->right_value, mem_assert->size);
+
+		string_stream_add(stream, "\n");
+
+		string_stream_add(stream, KUNIT_SUBSUBTEST_INDENT "%s ==\n",
+				mem_assert->text->right_text);
+		kunit_assert_hexdump(stream, mem_assert->right_value,
+					mem_assert->left_value, mem_assert->size);
+
+		kunit_assert_print_msg(message, stream);
+	}
+}
+EXPORT_SYMBOL_GPL(kunit_mem_assert_format);