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, 495 insertions, 0 deletions

diff --git a/scripts/dtc/util.c b/scripts/dtc/util.c
new file mode 100644
index 000000000..412592320
--- /dev/null
+++ b/scripts/dtc/util.c
@@ -0,0 +1,495 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright 2011 The Chromium Authors, All Rights Reserved.
+ * Copyright 2008 Jon Loeliger, Freescale Semiconductor, Inc.
+ *
+ * util_is_printable_string contributed by
+ *	Pantelis Antoniou <pantelis.antoniou AT gmail.com>
+ */
+
+#include <ctype.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdarg.h>
+#include <string.h>
+#include <assert.h>
+#include <inttypes.h>
+
+#include <errno.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+#include "libfdt.h"
+#include "util.h"
+#include "version_gen.h"
+
+void fprint_path_escaped(FILE *fp, const char *path)
+{
+	const char *p = path;
+
+	while (*p) {
+		if (*p == ' ') {
+			fputc('\\', fp);
+			fputc(' ', fp);
+		} else {
+			fputc(*p, fp);
+		}
+
+		p++;
+	}
+}
+
+char *xstrdup(const char *s)
+{
+	int len = strlen(s) + 1;
+	char *d = xmalloc(len);
+
+	memcpy(d, s, len);
+
+	return d;
+}
+
+char *xstrndup(const char *s, size_t n)
+{
+	size_t len = strnlen(s, n) + 1;
+	char *d = xmalloc(len);
+
+	memcpy(d, s, len - 1);
+	d[len - 1] = '\0';
+
+	return d;
+}
+
+int xavsprintf_append(char **strp, const char *fmt, va_list ap)
+{
+	int n, size = 0;	/* start with 128 bytes */
+	char *p;
+	va_list ap_copy;
+
+	p = *strp;
+	if (p)
+		size = strlen(p);
+
+	va_copy(ap_copy, ap);
+	n = vsnprintf(NULL, 0, fmt, ap_copy) + 1;
+	va_end(ap_copy);
+
+	p = xrealloc(p, size + n);
+
+	n = vsnprintf(p + size, n, fmt, ap);
+
+	*strp = p;
+	return strlen(p);
+}
+
+int xasprintf_append(char **strp, const char *fmt, ...)
+{
+	int n;
+	va_list ap;
+
+	va_start(ap, fmt);
+	n = xavsprintf_append(strp, fmt, ap);
+	va_end(ap);
+
+	return n;
+}
+
+int xasprintf(char **strp, const char *fmt, ...)
+{
+	int n;
+	va_list ap;
+
+	*strp = NULL;
+
+	va_start(ap, fmt);
+	n = xavsprintf_append(strp, fmt, ap);
+	va_end(ap);
+
+	return n;
+}
+
+char *join_path(const char *path, const char *name)
+{
+	int lenp = strlen(path);
+	int lenn = strlen(name);
+	int len;
+	int needslash = 1;
+	char *str;
+
+	len = lenp + lenn + 2;
+	if ((lenp > 0) && (path[lenp-1] == '/')) {
+		needslash = 0;
+		len--;
+	}
+
+	str = xmalloc(len);
+	memcpy(str, path, lenp);
+	if (needslash) {
+		str[lenp] = '/';
+		lenp++;
+	}
+	memcpy(str+lenp, name, lenn+1);
+	return str;
+}
+
+bool util_is_printable_string(const void *data, int len)
+{
+	const char *s = data;
+	const char *ss, *se;
+
+	/* zero length is not */
+	if (len == 0)
+		return 0;
+
+	/* must terminate with zero */
+	if (s[len - 1] != '\0')
+		return 0;
+
+	se = s + len;
+
+	while (s < se) {
+		ss = s;
+		while (s < se && *s && isprint((unsigned char)*s))
+			s++;
+
+		/* not zero, or not done yet */
+		if (*s != '\0' || s == ss)
+			return 0;
+
+		s++;
+	}
+
+	return 1;
+}
+
+/*
+ * Parse a octal encoded character starting at index i in string s.  The
+ * resulting character will be returned and the index i will be updated to
+ * point at the character directly after the end of the encoding, this may be
+ * the '\0' terminator of the string.
+ */
+static char get_oct_char(const char *s, int *i)
+{
+	char x[4];
+	char *endx;
+	long val;
+
+	x[3] = '\0';
+	strncpy(x, s + *i, 3);
+
+	val = strtol(x, &endx, 8);
+
+	assert(endx > x);
+
+	(*i) += endx - x;
+	return val;
+}
+
+/*
+ * Parse a hexadecimal encoded character starting at index i in string s.  The
+ * resulting character will be returned and the index i will be updated to
+ * point at the character directly after the end of the encoding, this may be
+ * the '\0' terminator of the string.
+ */
+static char get_hex_char(const char *s, int *i)
+{
+	char x[3];
+	char *endx;
+	long val;
+
+	x[2] = '\0';
+	strncpy(x, s + *i, 2);
+
+	val = strtol(x, &endx, 16);
+	if (!(endx  > x))
+		die("\\x used with no following hex digits\n");
+
+	(*i) += endx - x;
+	return val;
+}
+
+char get_escape_char(const char *s, int *i)
+{
+	char	c = s[*i];
+	int	j = *i + 1;
+	char	val;
+
+	switch (c) {
+	case 'a':
+		val = '\a';
+		break;
+	case 'b':
+		val = '\b';
+		break;
+	case 't':
+		val = '\t';
+		break;
+	case 'n':
+		val = '\n';
+		break;
+	case 'v':
+		val = '\v';
+		break;
+	case 'f':
+		val = '\f';
+		break;
+	case 'r':
+		val = '\r';
+		break;
+	case '0':
+	case '1':
+	case '2':
+	case '3':
+	case '4':
+	case '5':
+	case '6':
+	case '7':
+		j--; /* need to re-read the first digit as
+		      * part of the octal value */
+		val = get_oct_char(s, &j);
+		break;
+	case 'x':
+		val = get_hex_char(s, &j);
+		break;
+	default:
+		val = c;
+	}
+
+	(*i) = j;
+	return val;
+}
+
+int utilfdt_read_err(const char *filename, char **buffp, size_t *len)
+{
+	int fd = 0;	/* assume stdin */
+	char *buf = NULL;
+	size_t bufsize = 1024, offset = 0;
+	int ret = 0;
+
+	*buffp = NULL;
+	if (strcmp(filename, "-") != 0) {
+		fd = open(filename, O_RDONLY);
+		if (fd < 0)
+			return errno;
+	}
+
+	/* Loop until we have read everything */
+	buf = xmalloc(bufsize);
+	do {
+		/* Expand the buffer to hold the next chunk */
+		if (offset == bufsize) {
+			bufsize *= 2;
+			buf = xrealloc(buf, bufsize);
+		}
+
+		ret = read(fd, &buf[offset], bufsize - offset);
+		if (ret < 0) {
+			ret = errno;
+			break;
+		}
+		offset += ret;
+	} while (ret != 0);
+
+	/* Clean up, including closing stdin; return errno on error */
+	close(fd);
+	if (ret)
+		free(buf);
+	else
+		*buffp = buf;
+	if (len)
+		*len = bufsize;
+	return ret;
+}
+
+char *utilfdt_read(const char *filename, size_t *len)
+{
+	char *buff;
+	int ret = utilfdt_read_err(filename, &buff, len);
+
+	if (ret) {
+		fprintf(stderr, "Couldn't open blob from '%s': %s\n", filename,
+			strerror(ret));
+		return NULL;
+	}
+	/* Successful read */
+	return buff;
+}
+
+int utilfdt_write_err(const char *filename, const void *blob)
+{
+	int fd = 1;	/* assume stdout */
+	int totalsize;
+	int offset;
+	int ret = 0;
+	const char *ptr = blob;
+
+	if (strcmp(filename, "-") != 0) {
+		fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666);
+		if (fd < 0)
+			return errno;
+	}
+
+	totalsize = fdt_totalsize(blob);
+	offset = 0;
+
+	while (offset < totalsize) {
+		ret = write(fd, ptr + offset, totalsize - offset);
+		if (ret < 0) {
+			ret = -errno;
+			break;
+		}
+		offset += ret;
+	}
+	/* Close the file/stdin; return errno on error */
+	if (fd != 1)
+		close(fd);
+	return ret < 0 ? -ret : 0;
+}
+
+
+int utilfdt_write(const char *filename, const void *blob)
+{
+	int ret = utilfdt_write_err(filename, blob);
+
+	if (ret) {
+		fprintf(stderr, "Couldn't write blob to '%s': %s\n", filename,
+			strerror(ret));
+	}
+	return ret ? -1 : 0;
+}
+
+int utilfdt_decode_type(const char *fmt, int *type, int *size)
+{
+	int qualifier = 0;
+
+	if (!*fmt)
+		return -1;
+
+	/* get the conversion qualifier */
+	*size = -1;
+	if (strchr("hlLb", *fmt)) {
+		qualifier = *fmt++;
+		if (qualifier == *fmt) {
+			switch (*fmt++) {
+/* TODO:		case 'l': qualifier = 'L'; break;*/
+			case 'h':
+				qualifier = 'b';
+				break;
+			}
+		}
+	}
+
+	/* we should now have a type */
+	if ((*fmt == '\0') || !strchr("iuxsr", *fmt))
+		return -1;
+
+	/* convert qualifier (bhL) to byte size */
+	if (*fmt != 's' && *fmt != 'r')
+		*size = qualifier == 'b' ? 1 :
+				qualifier == 'h' ? 2 :
+				qualifier == 'l' ? 4 : -1;
+	*type = *fmt++;
+
+	/* that should be it! */
+	if (*fmt)
+		return -1;
+	return 0;
+}
+
+void utilfdt_print_data(const char *data, int len)
+{
+	int i;
+	const char *s;
+
+	/* no data, don't print */
+	if (len == 0)
+		return;
+
+	if (util_is_printable_string(data, len)) {
+		printf(" = ");
+
+		s = data;
+		do {
+			printf("\"%s\"", s);
+			s += strlen(s) + 1;
+			if (s < data + len)
+				printf(", ");
+		} while (s < data + len);
+
+	} else if ((len % 4) == 0) {
+		const fdt32_t *cell = (const fdt32_t *)data;
+
+		printf(" = <");
+		for (i = 0, len /= 4; i < len; i++)
+			printf("0x%08" PRIx32 "%s", fdt32_to_cpu(cell[i]),
+			       i < (len - 1) ? " " : "");
+		printf(">");
+	} else {
+		const unsigned char *p = (const unsigned char *)data;
+		printf(" = [");
+		for (i = 0; i < len; i++)
+			printf("%02x%s", *p++, i < len - 1 ? " " : "");
+		printf("]");
+	}
+}
+
+void NORETURN util_version(void)
+{
+	printf("Version: %s\n", DTC_VERSION);
+	exit(0);
+}
+
+void NORETURN util_usage(const char *errmsg, const char *synopsis,
+			 const char *short_opts,
+			 struct option const long_opts[],
+			 const char * const opts_help[])
+{
+	FILE *fp = errmsg ? stderr : stdout;
+	const char a_arg[] = "<arg>";
+	size_t a_arg_len = strlen(a_arg) + 1;
+	size_t i;
+	int optlen;
+
+	fprintf(fp,
+		"Usage: %s\n"
+		"\n"
+		"Options: -[%s]\n", synopsis, short_opts);
+
+	/* prescan the --long opt length to auto-align */
+	optlen = 0;
+	for (i = 0; long_opts[i].name; ++i) {
+		/* +1 is for space between --opt and help text */
+		int l = strlen(long_opts[i].name) + 1;
+		if (long_opts[i].has_arg == a_argument)
+			l += a_arg_len;
+		if (optlen < l)
+			optlen = l;
+	}
+
+	for (i = 0; long_opts[i].name; ++i) {
+		/* helps when adding new applets or options */
+		assert(opts_help[i] != NULL);
+
+		/* first output the short flag if it has one */
+		if (long_opts[i].val > '~')
+			fprintf(fp, "      ");
+		else
+			fprintf(fp, "  -%c, ", long_opts[i].val);
+
+		/* then the long flag */
+		if (long_opts[i].has_arg == no_argument)
+			fprintf(fp, "--%-*s", optlen, long_opts[i].name);
+		else
+			fprintf(fp, "--%s %s%*s", long_opts[i].name, a_arg,
+				(int)(optlen - strlen(long_opts[i].name) - a_arg_len), "");
+
+		/* finally the help text */
+		fprintf(fp, "%s\n", opts_help[i]);
+	}
+
+	if (errmsg) {
+		fprintf(fp, "\nError: %s\n", errmsg);
+		exit(EXIT_FAILURE);
+	} else
+		exit(EXIT_SUCCESS);
+}