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, 194 insertions, 0 deletions

diff --git a/scripts/parse-maintainers.pl b/scripts/parse-maintainers.pl
new file mode 100755
index 000000000..2ca4eb3f1
--- /dev/null
+++ b/scripts/parse-maintainers.pl
@@ -0,0 +1,194 @@
+#!/usr/bin/perl -w
+# SPDX-License-Identifier: GPL-2.0
+
+use strict;
+use Getopt::Long qw(:config no_auto_abbrev);
+
+my $input_file = "MAINTAINERS";
+my $output_file = "MAINTAINERS.new";
+my $output_section = "SECTION.new";
+my $help = 0;
+my $order = 0;
+my $P = $0;
+
+if (!GetOptions(
+		'input=s' => \$input_file,
+		'output=s' => \$output_file,
+		'section=s' => \$output_section,
+		'order!' => \$order,
+		'h|help|usage' => \$help,
+	    )) {
+    die "$P: invalid argument - use --help if necessary\n";
+}
+
+if ($help != 0) {
+    usage();
+    exit 0;
+}
+
+sub usage {
+    print <<EOT;
+usage: $P [options] <pattern matching regexes>
+
+  --input => MAINTAINERS file to read (default: MAINTAINERS)
+  --output => sorted MAINTAINERS file to write (default: MAINTAINERS.new)
+  --section => new sorted MAINTAINERS file to write to (default: SECTION.new)
+  --order => Use the preferred section content output ordering (default: 0)
+    Preferred ordering of section output is:
+      M:  Person acting as a maintainer
+      R:  Person acting as a patch reviewer
+      L:  Mailing list where patches should be sent
+      S:  Maintenance status
+      W:  URI for general information
+      Q:  URI for patchwork tracking
+      B:  URI for bug tracking/submission
+      C:  URI for chat
+      P:  URI or file for subsystem specific coding styles
+      T:  SCM tree type and location
+      F:  File and directory pattern
+      X:  File and directory exclusion pattern
+      N:  File glob
+      K:  Keyword - patch content regex
+
+If <pattern match regexes> exist, then the sections that match the
+regexes are not written to the output file but are written to the
+section file.
+
+EOT
+}
+
+# sort comparison functions
+sub by_category($$) {
+    my ($a, $b) = @_;
+
+    $a = uc $a;
+    $b = uc $b;
+
+    # This always sorts last
+    $a =~ s/THE REST/ZZZZZZ/g;
+    $b =~ s/THE REST/ZZZZZZ/g;
+
+    return $a cmp $b;
+}
+
+sub by_pattern($$) {
+    my ($a, $b) = @_;
+    my $preferred_order = 'MRLSWQBCPTFXNK';
+
+    my $a1 = uc(substr($a, 0, 1));
+    my $b1 = uc(substr($b, 0, 1));
+
+    my $a_index = index($preferred_order, $a1);
+    my $b_index = index($preferred_order, $b1);
+
+    $a_index = 1000 if ($a_index == -1);
+    $b_index = 1000 if ($b_index == -1);
+
+    if (($a1 =~ /^F$/ && $b1 =~ /^F$/) ||
+	($a1 =~ /^X$/ && $b1 =~ /^X$/)) {
+	return $a cmp $b;
+    }
+
+    if ($a_index < $b_index) {
+	return -1;
+    } elsif ($a_index == $b_index) {
+	return 0;
+    } else {
+	return 1;
+    }
+}
+
+sub trim {
+    my $s = shift;
+    $s =~ s/\s+$//;
+    $s =~ s/^\s+//;
+    return $s;
+}
+
+sub alpha_output {
+    my ($hashref, $filename) = (@_);
+
+    return if ! scalar(keys %$hashref);
+
+    open(my $file, '>', "$filename") or die "$P: $filename: open failed - $!\n";
+    my $separator;
+    foreach my $key (sort by_category keys %$hashref) {
+	if ($key eq " ") {
+	    print $file $$hashref{$key};
+	} else {
+	    if (! defined $separator) {
+		$separator = "\n";
+	    } else {
+		print $file $separator;
+	    }
+	    print $file $key . "\n";
+	    if ($order) {
+		foreach my $pattern (sort by_pattern split('\n', %$hashref{$key})) {
+		    print $file ($pattern . "\n");
+		}
+	    } else {
+		foreach my $pattern (split('\n', %$hashref{$key})) {
+		    print $file ($pattern . "\n");
+		}
+	    }
+	}
+    }
+    close($file);
+}
+
+sub file_input {
+    my ($hashref, $filename) = (@_);
+
+    my $lastline = "";
+    my $case = " ";
+    $$hashref{$case} = "";
+
+    open(my $file, '<', "$filename") or die "$P: $filename: open failed - $!\n";
+
+    while (<$file>) {
+        my $line = $_;
+
+        # Pattern line?
+        if ($line =~ m/^([A-Z]):\s*(.*)/) {
+            $line = $1 . ":\t" . trim($2) . "\n";
+            if ($lastline eq "") {
+                $$hashref{$case} = $$hashref{$case} . $line;
+                next;
+            }
+            $case = trim($lastline);
+            exists $$hashref{$case} and die "Header '$case' already exists";
+            $$hashref{$case} = $line;
+            $lastline = "";
+            next;
+        }
+
+        if ($case eq " ") {
+            $$hashref{$case} = $$hashref{$case} . $lastline;
+            $lastline = $line;
+            next;
+        }
+        trim($lastline) eq "" or die ("Odd non-pattern line '$lastline' for '$case'");
+        $lastline = $line;
+    }
+    $$hashref{$case} = $$hashref{$case} . $lastline;
+    close($file);
+}
+
+my %hash;
+my %new_hash;
+
+file_input(\%hash, $input_file);
+
+foreach my $type (@ARGV) {
+    foreach my $key (keys %hash) {
+	if ($key =~ /$type/ || $hash{$key} =~ /$type/) {
+	    $new_hash{$key} = $hash{$key};
+	    delete $hash{$key};
+	}
+    }
+}
+
+alpha_output(\%hash, $output_file);
+alpha_output(\%new_hash, $output_section);
+
+exit(0);