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, 373 insertions, 0 deletions

diff --git a/drivers/regulator/virtual.c b/drivers/regulator/virtual.c
new file mode 100644
index 000000000..218a0d66a
--- /dev/null
+++ b/drivers/regulator/virtual.c
@@ -0,0 +1,373 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * reg-virtual-consumer.c
+ *
+ * Copyright 2008 Wolfson Microelectronics PLC.
+ *
+ * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
+ */
+
+#include <linux/err.h>
+#include <linux/mutex.h>
+#include <linux/platform_device.h>
+#include <linux/regulator/consumer.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/of.h>
+
+struct virtual_consumer_data {
+	struct mutex lock;
+	struct regulator *regulator;
+	bool enabled;
+	int min_uV;
+	int max_uV;
+	int min_uA;
+	int max_uA;
+	unsigned int mode;
+};
+
+static void update_voltage_constraints(struct device *dev,
+				       struct virtual_consumer_data *data)
+{
+	int ret;
+
+	if (data->min_uV && data->max_uV
+	    && data->min_uV <= data->max_uV) {
+		dev_dbg(dev, "Requesting %d-%duV\n",
+			data->min_uV, data->max_uV);
+		ret = regulator_set_voltage(data->regulator,
+					data->min_uV, data->max_uV);
+		if (ret != 0) {
+			dev_err(dev,
+				"regulator_set_voltage() failed: %d\n", ret);
+			return;
+		}
+	}
+
+	if (data->min_uV && data->max_uV && !data->enabled) {
+		dev_dbg(dev, "Enabling regulator\n");
+		ret = regulator_enable(data->regulator);
+		if (ret == 0)
+			data->enabled = true;
+		else
+			dev_err(dev, "regulator_enable() failed: %d\n",
+				ret);
+	}
+
+	if (!(data->min_uV && data->max_uV) && data->enabled) {
+		dev_dbg(dev, "Disabling regulator\n");
+		ret = regulator_disable(data->regulator);
+		if (ret == 0)
+			data->enabled = false;
+		else
+			dev_err(dev, "regulator_disable() failed: %d\n",
+				ret);
+	}
+}
+
+static void update_current_limit_constraints(struct device *dev,
+					  struct virtual_consumer_data *data)
+{
+	int ret;
+
+	if (data->max_uA
+	    && data->min_uA <= data->max_uA) {
+		dev_dbg(dev, "Requesting %d-%duA\n",
+			data->min_uA, data->max_uA);
+		ret = regulator_set_current_limit(data->regulator,
+					data->min_uA, data->max_uA);
+		if (ret != 0) {
+			dev_err(dev,
+				"regulator_set_current_limit() failed: %d\n",
+				ret);
+			return;
+		}
+	}
+
+	if (data->max_uA && !data->enabled) {
+		dev_dbg(dev, "Enabling regulator\n");
+		ret = regulator_enable(data->regulator);
+		if (ret == 0)
+			data->enabled = true;
+		else
+			dev_err(dev, "regulator_enable() failed: %d\n",
+				ret);
+	}
+
+	if (!(data->min_uA && data->max_uA) && data->enabled) {
+		dev_dbg(dev, "Disabling regulator\n");
+		ret = regulator_disable(data->regulator);
+		if (ret == 0)
+			data->enabled = false;
+		else
+			dev_err(dev, "regulator_disable() failed: %d\n",
+				ret);
+	}
+}
+
+static ssize_t show_min_uV(struct device *dev,
+			   struct device_attribute *attr, char *buf)
+{
+	struct virtual_consumer_data *data = dev_get_drvdata(dev);
+	return sprintf(buf, "%d\n", data->min_uV);
+}
+
+static ssize_t set_min_uV(struct device *dev, struct device_attribute *attr,
+			  const char *buf, size_t count)
+{
+	struct virtual_consumer_data *data = dev_get_drvdata(dev);
+	long val;
+
+	if (kstrtol(buf, 10, &val) != 0)
+		return count;
+
+	mutex_lock(&data->lock);
+
+	data->min_uV = val;
+	update_voltage_constraints(dev, data);
+
+	mutex_unlock(&data->lock);
+
+	return count;
+}
+
+static ssize_t show_max_uV(struct device *dev,
+			   struct device_attribute *attr, char *buf)
+{
+	struct virtual_consumer_data *data = dev_get_drvdata(dev);
+	return sprintf(buf, "%d\n", data->max_uV);
+}
+
+static ssize_t set_max_uV(struct device *dev, struct device_attribute *attr,
+			  const char *buf, size_t count)
+{
+	struct virtual_consumer_data *data = dev_get_drvdata(dev);
+	long val;
+
+	if (kstrtol(buf, 10, &val) != 0)
+		return count;
+
+	mutex_lock(&data->lock);
+
+	data->max_uV = val;
+	update_voltage_constraints(dev, data);
+
+	mutex_unlock(&data->lock);
+
+	return count;
+}
+
+static ssize_t show_min_uA(struct device *dev,
+			   struct device_attribute *attr, char *buf)
+{
+	struct virtual_consumer_data *data = dev_get_drvdata(dev);
+	return sprintf(buf, "%d\n", data->min_uA);
+}
+
+static ssize_t set_min_uA(struct device *dev, struct device_attribute *attr,
+			  const char *buf, size_t count)
+{
+	struct virtual_consumer_data *data = dev_get_drvdata(dev);
+	long val;
+
+	if (kstrtol(buf, 10, &val) != 0)
+		return count;
+
+	mutex_lock(&data->lock);
+
+	data->min_uA = val;
+	update_current_limit_constraints(dev, data);
+
+	mutex_unlock(&data->lock);
+
+	return count;
+}
+
+static ssize_t show_max_uA(struct device *dev,
+			   struct device_attribute *attr, char *buf)
+{
+	struct virtual_consumer_data *data = dev_get_drvdata(dev);
+	return sprintf(buf, "%d\n", data->max_uA);
+}
+
+static ssize_t set_max_uA(struct device *dev, struct device_attribute *attr,
+			  const char *buf, size_t count)
+{
+	struct virtual_consumer_data *data = dev_get_drvdata(dev);
+	long val;
+
+	if (kstrtol(buf, 10, &val) != 0)
+		return count;
+
+	mutex_lock(&data->lock);
+
+	data->max_uA = val;
+	update_current_limit_constraints(dev, data);
+
+	mutex_unlock(&data->lock);
+
+	return count;
+}
+
+static ssize_t show_mode(struct device *dev,
+			 struct device_attribute *attr, char *buf)
+{
+	struct virtual_consumer_data *data = dev_get_drvdata(dev);
+
+	switch (data->mode) {
+	case REGULATOR_MODE_FAST:
+		return sprintf(buf, "fast\n");
+	case REGULATOR_MODE_NORMAL:
+		return sprintf(buf, "normal\n");
+	case REGULATOR_MODE_IDLE:
+		return sprintf(buf, "idle\n");
+	case REGULATOR_MODE_STANDBY:
+		return sprintf(buf, "standby\n");
+	default:
+		return sprintf(buf, "unknown\n");
+	}
+}
+
+static ssize_t set_mode(struct device *dev, struct device_attribute *attr,
+			const char *buf, size_t count)
+{
+	struct virtual_consumer_data *data = dev_get_drvdata(dev);
+	unsigned int mode;
+	int ret;
+
+	/*
+	 * sysfs_streq() doesn't need the \n's, but we add them so the strings
+	 * will be shared with show_mode(), above.
+	 */
+	if (sysfs_streq(buf, "fast\n"))
+		mode = REGULATOR_MODE_FAST;
+	else if (sysfs_streq(buf, "normal\n"))
+		mode = REGULATOR_MODE_NORMAL;
+	else if (sysfs_streq(buf, "idle\n"))
+		mode = REGULATOR_MODE_IDLE;
+	else if (sysfs_streq(buf, "standby\n"))
+		mode = REGULATOR_MODE_STANDBY;
+	else {
+		dev_err(dev, "Configuring invalid mode\n");
+		return count;
+	}
+
+	mutex_lock(&data->lock);
+	ret = regulator_set_mode(data->regulator, mode);
+	if (ret == 0)
+		data->mode = mode;
+	else
+		dev_err(dev, "Failed to configure mode: %d\n", ret);
+	mutex_unlock(&data->lock);
+
+	return count;
+}
+
+static DEVICE_ATTR(min_microvolts, 0664, show_min_uV, set_min_uV);
+static DEVICE_ATTR(max_microvolts, 0664, show_max_uV, set_max_uV);
+static DEVICE_ATTR(min_microamps, 0664, show_min_uA, set_min_uA);
+static DEVICE_ATTR(max_microamps, 0664, show_max_uA, set_max_uA);
+static DEVICE_ATTR(mode, 0664, show_mode, set_mode);
+
+static struct attribute *regulator_virtual_attributes[] = {
+	&dev_attr_min_microvolts.attr,
+	&dev_attr_max_microvolts.attr,
+	&dev_attr_min_microamps.attr,
+	&dev_attr_max_microamps.attr,
+	&dev_attr_mode.attr,
+	NULL
+};
+
+static const struct attribute_group regulator_virtual_attr_group = {
+	.attrs	= regulator_virtual_attributes,
+};
+
+#ifdef CONFIG_OF
+static const struct of_device_id regulator_virtual_consumer_of_match[] = {
+	{ .compatible = "regulator-virtual-consumer" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, regulator_virtual_consumer_of_match);
+#endif
+
+static int regulator_virtual_probe(struct platform_device *pdev)
+{
+	char *reg_id = dev_get_platdata(&pdev->dev);
+	struct virtual_consumer_data *drvdata;
+	static bool warned;
+	int ret;
+
+	if (!warned) {
+		warned = true;
+		pr_warn("**********************************************************\n");
+		pr_warn("**   NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE   **\n");
+		pr_warn("**                                                      **\n");
+		pr_warn("** regulator-virtual-consumer is only for testing and   **\n");
+		pr_warn("** debugging.  Do not use it in a production kernel.    **\n");
+		pr_warn("**                                                      **\n");
+		pr_warn("**   NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE   **\n");
+		pr_warn("**********************************************************\n");
+	}
+
+	drvdata = devm_kzalloc(&pdev->dev, sizeof(struct virtual_consumer_data),
+			       GFP_KERNEL);
+	if (drvdata == NULL)
+		return -ENOMEM;
+
+	/*
+	 * This virtual consumer does not have any hardware-defined supply
+	 * name, so just allow the regulator to be specified in a property
+	 * named "default-supply" when we're being probed from devicetree.
+	 */
+	if (!reg_id && pdev->dev.of_node)
+		reg_id = "default";
+
+	mutex_init(&drvdata->lock);
+
+	drvdata->regulator = devm_regulator_get(&pdev->dev, reg_id);
+	if (IS_ERR(drvdata->regulator))
+		return dev_err_probe(&pdev->dev, PTR_ERR(drvdata->regulator),
+				     "Failed to obtain supply '%s'\n",
+				     reg_id);
+
+	ret = sysfs_create_group(&pdev->dev.kobj,
+				 &regulator_virtual_attr_group);
+	if (ret != 0) {
+		dev_err(&pdev->dev,
+			"Failed to create attribute group: %d\n", ret);
+		return ret;
+	}
+
+	drvdata->mode = regulator_get_mode(drvdata->regulator);
+
+	platform_set_drvdata(pdev, drvdata);
+
+	return 0;
+}
+
+static void regulator_virtual_remove(struct platform_device *pdev)
+{
+	struct virtual_consumer_data *drvdata = platform_get_drvdata(pdev);
+
+	sysfs_remove_group(&pdev->dev.kobj, &regulator_virtual_attr_group);
+
+	if (drvdata->enabled)
+		regulator_disable(drvdata->regulator);
+}
+
+static struct platform_driver regulator_virtual_consumer_driver = {
+	.probe		= regulator_virtual_probe,
+	.remove		= regulator_virtual_remove,
+	.driver		= {
+		.name		= "reg-virt-consumer",
+		.probe_type	= PROBE_PREFER_ASYNCHRONOUS,
+		.of_match_table = of_match_ptr(regulator_virtual_consumer_of_match),
+	},
+};
+
+module_platform_driver(regulator_virtual_consumer_driver);
+
+MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
+MODULE_DESCRIPTION("Virtual regulator consumer");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:reg-virt-consumer");