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, 131 insertions, 0 deletions

diff --git a/scripts/macro_checker.py b/scripts/macro_checker.py
new file mode 100755
index 000000000..ba550982e
--- /dev/null
+++ b/scripts/macro_checker.py
@@ -0,0 +1,131 @@
+#!/usr/bin/python3
+# SPDX-License-Identifier: GPL-2.0
+# Author: Julian Sun <sunjunchao2870@gmail.com>
+
+""" Find macro definitions with unused parameters. """
+
+import argparse
+import os
+import re
+
+parser = argparse.ArgumentParser()
+
+parser.add_argument("path", type=str, help="The file or dir path that needs check")
+parser.add_argument("-v", "--verbose", action="store_true",
+                    help="Check conditional macros, but may lead to more false positives")
+args = parser.parse_args()
+
+macro_pattern = r"#define\s+(\w+)\(([^)]*)\)"
+# below vars were used to reduce false positives
+fp_patterns = [r"\s*do\s*\{\s*\}\s*while\s*\(\s*0\s*\)",
+               r"\(?0\)?", r"\(?1\)?"]
+correct_macros = []
+cond_compile_mark = "#if"
+cond_compile_end = "#endif"
+
+def check_macro(macro_line, report):
+    match = re.match(macro_pattern, macro_line)
+    if match:
+        macro_def = re.sub(macro_pattern, '', macro_line)
+        identifier = match.group(1)
+        content = match.group(2)
+        arguments = [item.strip() for item in content.split(',') if item.strip()]
+
+        macro_def = macro_def.strip()
+        if not macro_def:
+            return
+        # used to reduce false positives, like #define endfor_nexthops(rt) }
+        if len(macro_def) == 1:
+            return
+
+        for fp_pattern in fp_patterns:
+            if (re.match(fp_pattern, macro_def)):
+                return
+
+        for arg in arguments:
+            # used to reduce false positives
+            if "..." in arg:
+                return
+        for arg in arguments:
+            if not arg in macro_def and report == False:
+                return
+            # if there is a correct macro with the same name, do not report it.
+            if not arg in macro_def and identifier not in correct_macros:
+                print(f"Argument {arg} is not used in function-line macro {identifier}")
+                return
+
+        correct_macros.append(identifier)
+
+
+# remove comment and whitespace
+def macro_strip(macro):
+    comment_pattern1 = r"\/\/*"
+    comment_pattern2 = r"\/\**\*\/"
+
+    macro = macro.strip()
+    macro = re.sub(comment_pattern1, '', macro)
+    macro = re.sub(comment_pattern2, '', macro)
+
+    return macro
+
+def file_check_macro(file_path, report):
+    # number of conditional compiling
+    cond_compile = 0
+    # only check .c and .h file
+    if not file_path.endswith(".c") and not file_path.endswith(".h"):
+        return
+
+    with open(file_path, "r") as f:
+        while True:
+            line = f.readline()
+            if not line:
+                break
+            line = line.strip()
+            if line.startswith(cond_compile_mark):
+                cond_compile += 1
+                continue
+            if line.startswith(cond_compile_end):
+                cond_compile -= 1
+                continue
+
+            macro = re.match(macro_pattern, line)
+            if macro:
+                macro = macro_strip(macro.string)
+                while macro[-1] == '\\':
+                    macro = macro[0:-1]
+                    macro = macro.strip()
+                    macro += f.readline()
+                    macro = macro_strip(macro)
+                if not args.verbose:
+                    if file_path.endswith(".c")  and cond_compile != 0:
+                        continue
+                    # 1 is for #ifdef xxx at the beginning of the header file
+                    if file_path.endswith(".h") and cond_compile != 1:
+                        continue
+                check_macro(macro, report)
+
+def get_correct_macros(path):
+    file_check_macro(path, False)
+
+def dir_check_macro(dir_path):
+
+    for dentry in os.listdir(dir_path):
+        path = os.path.join(dir_path, dentry)
+        if os.path.isdir(path):
+            dir_check_macro(path)
+        elif os.path.isfile(path):
+            get_correct_macros(path)
+            file_check_macro(path, True)
+
+
+def main():
+    if os.path.isfile(args.path):
+        get_correct_macros(args.path)
+        file_check_macro(args.path, True)
+    elif os.path.isdir(args.path):
+        dir_check_macro(args.path)
+    else:
+        print(f"{args.path} doesn't exit or is neither a file nor a dir")
+
+if __name__ == "__main__":
+    main()
\ No newline at end of file