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, 328 insertions, 0 deletions

diff --git a/drivers/md/dm-init.c b/drivers/md/dm-init.c
new file mode 100644
index 000000000..c1bacba92
--- /dev/null
+++ b/drivers/md/dm-init.c
@@ -0,0 +1,328 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+/*
+ * Copyright (C) 2017 The Chromium OS Authors <chromium-os-dev@chromium.org>
+ *
+ * This file is released under the GPLv2.
+ */
+
+#include <linux/ctype.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/device-mapper.h>
+#include <linux/init.h>
+#include <linux/list.h>
+#include <linux/moduleparam.h>
+
+#define DM_MSG_PREFIX "init"
+#define DM_MAX_DEVICES 256
+#define DM_MAX_TARGETS 256
+#define DM_MAX_STR_SIZE 4096
+#define DM_MAX_WAITFOR 256
+
+static char *create;
+
+static char *waitfor[DM_MAX_WAITFOR];
+
+/*
+ * Format: dm-mod.create=<name>,<uuid>,<minor>,<flags>,<table>[,<table>+][;<name>,<uuid>,<minor>,<flags>,<table>[,<table>+]+]
+ * Table format: <start_sector> <num_sectors> <target_type> <target_args>
+ * Block devices to wait for to become available before setting up tables:
+ * dm-mod.waitfor=<device1>[,..,<deviceN>]
+ *
+ * See Documentation/admin-guide/device-mapper/dm-init.rst for dm-mod.create="..." format
+ * details.
+ */
+
+struct dm_device {
+	struct dm_ioctl dmi;
+	struct dm_target_spec *table[DM_MAX_TARGETS];
+	char *target_args_array[DM_MAX_TARGETS];
+	struct list_head list;
+};
+
+static const char * const dm_allowed_targets[] __initconst = {
+	"crypt",
+	"delay",
+	"linear",
+	"snapshot-origin",
+	"striped",
+	"verity",
+};
+
+static int __init dm_verify_target_type(const char *target)
+{
+	unsigned int i;
+
+	for (i = 0; i < ARRAY_SIZE(dm_allowed_targets); i++) {
+		if (!strcmp(dm_allowed_targets[i], target))
+			return 0;
+	}
+	return -EINVAL;
+}
+
+static void __init dm_setup_cleanup(struct list_head *devices)
+{
+	struct dm_device *dev, *tmp;
+	unsigned int i;
+
+	list_for_each_entry_safe(dev, tmp, devices, list) {
+		list_del(&dev->list);
+		for (i = 0; i < dev->dmi.target_count; i++) {
+			kfree(dev->table[i]);
+			kfree(dev->target_args_array[i]);
+		}
+		kfree(dev);
+	}
+}
+
+/**
+ * str_field_delimit - delimit a string based on a separator char.
+ * @str: the pointer to the string to delimit.
+ * @separator: char that delimits the field
+ *
+ * Find a @separator and replace it by '\0'.
+ * Remove leading and trailing spaces.
+ * Return the remainder string after the @separator.
+ */
+static char __init *str_field_delimit(char **str, char separator)
+{
+	char *s;
+
+	/* TODO: add support for escaped characters */
+	*str = skip_spaces(*str);
+	s = strchr(*str, separator);
+	/* Delimit the field and remove trailing spaces */
+	if (s)
+		*s = '\0';
+	*str = strim(*str);
+	return s ? ++s : NULL;
+}
+
+/**
+ * dm_parse_table_entry - parse a table entry
+ * @dev: device to store the parsed information.
+ * @str: the pointer to a string with the format:
+ *	<start_sector> <num_sectors> <target_type> <target_args>[, ...]
+ *
+ * Return the remainder string after the table entry, i.e, after the comma which
+ * delimits the entry or NULL if reached the end of the string.
+ */
+static char __init *dm_parse_table_entry(struct dm_device *dev, char *str)
+{
+	const unsigned int n = dev->dmi.target_count - 1;
+	struct dm_target_spec *sp;
+	unsigned int i;
+	/* fields:  */
+	char *field[4];
+	char *next;
+
+	field[0] = str;
+	/* Delimit first 3 fields that are separated by space */
+	for (i = 0; i < ARRAY_SIZE(field) - 1; i++) {
+		field[i + 1] = str_field_delimit(&field[i], ' ');
+		if (!field[i + 1])
+			return ERR_PTR(-EINVAL);
+	}
+	/* Delimit last field that can be terminated by comma */
+	next = str_field_delimit(&field[i], ',');
+
+	sp = kzalloc_obj(*sp);
+	if (!sp)
+		return ERR_PTR(-ENOMEM);
+	dev->table[n] = sp;
+
+	/* start_sector */
+	if (kstrtoull(field[0], 0, &sp->sector_start))
+		return ERR_PTR(-EINVAL);
+	/* num_sector */
+	if (kstrtoull(field[1], 0, &sp->length))
+		return ERR_PTR(-EINVAL);
+	/* target_type */
+	strscpy(sp->target_type, field[2], sizeof(sp->target_type));
+	if (dm_verify_target_type(sp->target_type)) {
+		DMERR("invalid type \"%s\"", sp->target_type);
+		return ERR_PTR(-EINVAL);
+	}
+	/* target_args */
+	dev->target_args_array[n] = kstrndup(field[3], DM_MAX_STR_SIZE,
+					     GFP_KERNEL);
+	if (!dev->target_args_array[n])
+		return ERR_PTR(-ENOMEM);
+
+	return next;
+}
+
+/**
+ * dm_parse_table - parse "dm-mod.create=" table field
+ * @dev: device to store the parsed information.
+ * @str: the pointer to a string with the format:
+ *	<table>[,<table>+]
+ */
+static int __init dm_parse_table(struct dm_device *dev, char *str)
+{
+	char *table_entry = str;
+
+	while (table_entry) {
+		DMDEBUG("parsing table \"%s\"", str);
+		if (++dev->dmi.target_count > DM_MAX_TARGETS) {
+			DMERR("too many targets %u > %d",
+			      dev->dmi.target_count, DM_MAX_TARGETS);
+			return -EINVAL;
+		}
+		table_entry = dm_parse_table_entry(dev, table_entry);
+		if (IS_ERR(table_entry)) {
+			DMERR("couldn't parse table");
+			return PTR_ERR(table_entry);
+		}
+	}
+
+	return 0;
+}
+
+/**
+ * dm_parse_device_entry - parse a device entry
+ * @dev: device to store the parsed information.
+ * @str: the pointer to a string with the format:
+ *	name,uuid,minor,flags,table[; ...]
+ *
+ * Return the remainder string after the table entry, i.e, after the semi-colon
+ * which delimits the entry or NULL if reached the end of the string.
+ */
+static char __init *dm_parse_device_entry(struct dm_device *dev, char *str)
+{
+	/* There are 5 fields: name,uuid,minor,flags,table; */
+	char *field[5];
+	unsigned int i;
+	char *next;
+
+	field[0] = str;
+	/* Delimit first 4 fields that are separated by comma */
+	for (i = 0; i < ARRAY_SIZE(field) - 1; i++) {
+		field[i+1] = str_field_delimit(&field[i], ',');
+		if (!field[i+1])
+			return ERR_PTR(-EINVAL);
+	}
+	/* Delimit last field that can be delimited by semi-colon */
+	next = str_field_delimit(&field[i], ';');
+
+	/* name */
+	strscpy(dev->dmi.name, field[0], sizeof(dev->dmi.name));
+	/* uuid */
+	strscpy(dev->dmi.uuid, field[1], sizeof(dev->dmi.uuid));
+	/* minor */
+	if (strlen(field[2])) {
+		if (kstrtoull(field[2], 0, &dev->dmi.dev) ||
+		    dev->dmi.dev >= (1 << MINORBITS))
+			return ERR_PTR(-EINVAL);
+		dev->dmi.dev = huge_encode_dev((dev_t)dev->dmi.dev);
+		dev->dmi.flags |= DM_PERSISTENT_DEV_FLAG;
+	}
+	/* flags */
+	if (!strcmp(field[3], "ro"))
+		dev->dmi.flags |= DM_READONLY_FLAG;
+	else if (strcmp(field[3], "rw"))
+		return ERR_PTR(-EINVAL);
+	/* table */
+	if (dm_parse_table(dev, field[4]))
+		return ERR_PTR(-EINVAL);
+
+	return next;
+}
+
+/**
+ * dm_parse_devices - parse "dm-mod.create=" argument
+ * @devices: list of struct dm_device to store the parsed information.
+ * @str: the pointer to a string with the format:
+ *	<device>[;<device>+]
+ */
+static int __init dm_parse_devices(struct list_head *devices, char *str)
+{
+	unsigned long ndev = 0;
+	struct dm_device *dev;
+	char *device = str;
+
+	DMDEBUG("parsing \"%s\"", str);
+	while (device) {
+		dev = kzalloc_obj(*dev);
+		if (!dev)
+			return -ENOMEM;
+		list_add_tail(&dev->list, devices);
+
+		if (++ndev > DM_MAX_DEVICES) {
+			DMERR("too many devices %lu > %d",
+			      ndev, DM_MAX_DEVICES);
+			return -EINVAL;
+		}
+
+		device = dm_parse_device_entry(dev, device);
+		if (IS_ERR(device)) {
+			DMERR("couldn't parse device");
+			return PTR_ERR(device);
+		}
+	}
+
+	return 0;
+}
+
+/**
+ * dm_init_init - parse "dm-mod.create=" argument and configure drivers
+ */
+static int __init dm_init_init(void)
+{
+	struct dm_device *dev;
+	LIST_HEAD(devices);
+	char *str;
+	int i, r;
+
+	if (!create)
+		return 0;
+
+	if (strlen(create) >= DM_MAX_STR_SIZE) {
+		DMERR("Argument is too big. Limit is %d", DM_MAX_STR_SIZE);
+		return -EINVAL;
+	}
+	str = kstrndup(create, DM_MAX_STR_SIZE, GFP_KERNEL);
+	if (!str)
+		return -ENOMEM;
+
+	r = dm_parse_devices(&devices, str);
+	if (r)
+		goto out;
+
+	DMINFO("waiting for all devices to be available before creating mapped devices");
+	wait_for_device_probe();
+
+	for (i = 0; i < ARRAY_SIZE(waitfor); i++) {
+		if (waitfor[i]) {
+			dev_t dev;
+
+			DMINFO("waiting for device %s ...", waitfor[i]);
+			while (early_lookup_bdev(waitfor[i], &dev))
+				fsleep(5000);
+		}
+	}
+
+	if (waitfor[0]) {
+		wait_for_device_probe();
+		DMINFO("all devices available");
+	}
+
+	list_for_each_entry(dev, &devices, list) {
+		if (dm_early_create(&dev->dmi, dev->table,
+				    dev->target_args_array))
+			break;
+	}
+out:
+	kfree(str);
+	dm_setup_cleanup(&devices);
+	return r;
+}
+
+late_initcall(dm_init_init);
+
+module_param(create, charp, 0);
+MODULE_PARM_DESC(create, "Create a mapped device in early boot");
+
+module_param_array(waitfor, charp, NULL, 0);
+MODULE_PARM_DESC(waitfor, "Devices to wait for before setting up tables");