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, 225 insertions, 0 deletions

diff --git a/drivers/regulator/userspace-consumer.c b/drivers/regulator/userspace-consumer.c
new file mode 100644
index 000000000..72bb5ffb4
--- /dev/null
+++ b/drivers/regulator/userspace-consumer.c
@@ -0,0 +1,225 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * userspace-consumer.c
+ *
+ * Copyright 2009 CompuLab, Ltd.
+ *
+ * Author: Mike Rapoport <mike@compulab.co.il>
+ *
+ * Based of virtual consumer driver:
+ *   Copyright 2008 Wolfson Microelectronics PLC.
+ *   Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
+ */
+
+#include <linux/err.h>
+#include <linux/mutex.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/regulator/consumer.h>
+#include <linux/regulator/userspace-consumer.h>
+#include <linux/slab.h>
+
+struct userspace_consumer_data {
+	const char *name;
+
+	struct mutex lock;
+	bool enabled;
+	bool no_autoswitch;
+
+	int num_supplies;
+	struct regulator_bulk_data *supplies;
+};
+
+static ssize_t name_show(struct device *dev,
+			 struct device_attribute *attr, char *buf)
+{
+	struct userspace_consumer_data *data = dev_get_drvdata(dev);
+
+	return sprintf(buf, "%s\n", data->name);
+}
+
+static ssize_t state_show(struct device *dev,
+			  struct device_attribute *attr, char *buf)
+{
+	struct userspace_consumer_data *data = dev_get_drvdata(dev);
+
+	if (data->enabled)
+		return sprintf(buf, "enabled\n");
+
+	return sprintf(buf, "disabled\n");
+}
+
+static ssize_t state_store(struct device *dev, struct device_attribute *attr,
+			   const char *buf, size_t count)
+{
+	struct userspace_consumer_data *data = dev_get_drvdata(dev);
+	bool enabled;
+	int ret;
+
+	/*
+	 * sysfs_streq() doesn't need the \n's, but we add them so the strings
+	 * will be shared with show_state(), above.
+	 */
+	if (sysfs_streq(buf, "enabled\n") || sysfs_streq(buf, "1"))
+		enabled = true;
+	else if (sysfs_streq(buf, "disabled\n") || sysfs_streq(buf, "0"))
+		enabled = false;
+	else {
+		dev_err(dev, "Configuring invalid mode\n");
+		return count;
+	}
+
+	mutex_lock(&data->lock);
+	if (enabled != data->enabled) {
+		if (enabled)
+			ret = regulator_bulk_enable(data->num_supplies,
+						    data->supplies);
+		else
+			ret = regulator_bulk_disable(data->num_supplies,
+						     data->supplies);
+
+		if (ret == 0)
+			data->enabled = enabled;
+		else
+			dev_err(dev, "Failed to configure state: %d\n", ret);
+	}
+	mutex_unlock(&data->lock);
+
+	return count;
+}
+
+static DEVICE_ATTR_RO(name);
+static DEVICE_ATTR_RW(state);
+
+static struct attribute *attributes[] = {
+	&dev_attr_name.attr,
+	&dev_attr_state.attr,
+	NULL,
+};
+
+static umode_t attr_visible(struct kobject *kobj, struct attribute *attr, int idx)
+{
+	struct device *dev = kobj_to_dev(kobj);
+	struct userspace_consumer_data *data = dev_get_drvdata(dev);
+
+	/* If a name hasn't been set, don't bother with the attribute */
+	if (attr == &dev_attr_name.attr && !data->name)
+		return 0;
+
+	return attr->mode;
+}
+
+static const struct attribute_group attr_group = {
+	.attrs	= attributes,
+	.is_visible =  attr_visible,
+};
+
+static int regulator_userspace_consumer_probe(struct platform_device *pdev)
+{
+	struct regulator_userspace_consumer_data tmpdata;
+	struct regulator_userspace_consumer_data *pdata;
+	struct userspace_consumer_data *drvdata;
+	int ret;
+
+	pdata = dev_get_platdata(&pdev->dev);
+	if (!pdata) {
+		if (!pdev->dev.of_node)
+			return -EINVAL;
+
+		pdata = &tmpdata;
+		memset(pdata, 0, sizeof(*pdata));
+
+		pdata->no_autoswitch = true;
+		pdata->num_supplies = 1;
+		pdata->supplies = devm_kzalloc(&pdev->dev, sizeof(*pdata->supplies), GFP_KERNEL);
+		if (!pdata->supplies)
+			return -ENOMEM;
+		pdata->supplies[0].supply = "vout";
+	}
+
+	if (pdata->num_supplies < 1) {
+		dev_err(&pdev->dev, "At least one supply required\n");
+		return -EINVAL;
+	}
+
+	drvdata = devm_kzalloc(&pdev->dev,
+			       sizeof(struct userspace_consumer_data),
+			       GFP_KERNEL);
+	if (drvdata == NULL)
+		return -ENOMEM;
+
+	drvdata->name = pdata->name;
+	drvdata->num_supplies = pdata->num_supplies;
+	drvdata->supplies = pdata->supplies;
+	drvdata->no_autoswitch = pdata->no_autoswitch;
+
+	mutex_init(&drvdata->lock);
+
+	ret = devm_regulator_bulk_get_exclusive(&pdev->dev, drvdata->num_supplies,
+						drvdata->supplies);
+	if (ret)
+		return dev_err_probe(&pdev->dev, ret, "Failed to get supplies\n");
+
+	platform_set_drvdata(pdev, drvdata);
+
+	ret = sysfs_create_group(&pdev->dev.kobj, &attr_group);
+	if (ret != 0)
+		return ret;
+
+	if (pdata->init_on && !pdata->no_autoswitch) {
+		ret = regulator_bulk_enable(drvdata->num_supplies,
+					    drvdata->supplies);
+		if (ret) {
+			dev_err(&pdev->dev,
+				"Failed to set initial state: %d\n", ret);
+			goto err_enable;
+		}
+	}
+
+	ret = regulator_is_enabled(pdata->supplies[0].consumer);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "Failed to get regulator status\n");
+		goto err_enable;
+	}
+	drvdata->enabled = !!ret;
+
+	return 0;
+
+err_enable:
+	sysfs_remove_group(&pdev->dev.kobj, &attr_group);
+
+	return ret;
+}
+
+static void regulator_userspace_consumer_remove(struct platform_device *pdev)
+{
+	struct userspace_consumer_data *data = platform_get_drvdata(pdev);
+
+	sysfs_remove_group(&pdev->dev.kobj, &attr_group);
+
+	if (data->enabled && !data->no_autoswitch)
+		regulator_bulk_disable(data->num_supplies, data->supplies);
+}
+
+static const struct of_device_id regulator_userspace_consumer_of_match[] = {
+	{ .compatible = "regulator-output", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, regulator_userspace_consumer_of_match);
+
+static struct platform_driver regulator_userspace_consumer_driver = {
+	.probe		= regulator_userspace_consumer_probe,
+	.remove		= regulator_userspace_consumer_remove,
+	.driver		= {
+		.name		= "reg-userspace-consumer",
+		.probe_type	= PROBE_PREFER_ASYNCHRONOUS,
+		.of_match_table	= regulator_userspace_consumer_of_match,
+	},
+};
+
+module_platform_driver(regulator_userspace_consumer_driver);
+
+MODULE_AUTHOR("Mike Rapoport <mike@compulab.co.il>");
+MODULE_DESCRIPTION("Userspace consumer for voltage and current regulators");
+MODULE_LICENSE("GPL");