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, 245 insertions, 0 deletions

diff --git a/drivers/rpmsg/rpmsg_ctrl.c b/drivers/rpmsg/rpmsg_ctrl.c
new file mode 100644
index 000000000..5c19188d0
--- /dev/null
+++ b/drivers/rpmsg/rpmsg_ctrl.c
@@ -0,0 +1,245 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2022, STMicroelectronics
+ * Copyright (c) 2016, Linaro Ltd.
+ * Copyright (c) 2012, Michal Simek <monstr@monstr.eu>
+ * Copyright (c) 2012, PetaLogix
+ * Copyright (c) 2011, Texas Instruments, Inc.
+ * Copyright (c) 2011, Google, Inc.
+ *
+ * Based on rpmsg performance statistics driver by Michal Simek, which in turn
+ * was based on TI & Google OMX rpmsg driver.
+ */
+
+#define pr_fmt(fmt)		KBUILD_MODNAME ": " fmt
+
+#include <linux/cdev.h>
+#include <linux/device.h>
+#include <linux/fs.h>
+#include <linux/idr.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/rpmsg.h>
+#include <linux/skbuff.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+#include <uapi/linux/rpmsg.h>
+
+#include "rpmsg_char.h"
+#include "rpmsg_internal.h"
+
+#define RPMSG_DEV_MAX	(MINORMASK + 1)
+
+static dev_t rpmsg_major;
+
+static DEFINE_IDA(rpmsg_ctrl_ida);
+static DEFINE_IDA(rpmsg_minor_ida);
+
+#define dev_to_ctrldev(dev) container_of(dev, struct rpmsg_ctrldev, dev)
+#define cdev_to_ctrldev(i_cdev) container_of(i_cdev, struct rpmsg_ctrldev, cdev)
+
+/**
+ * struct rpmsg_ctrldev - control device for instantiating endpoint devices
+ * @rpdev:	underlaying rpmsg device
+ * @cdev:	cdev for the ctrl device
+ * @dev:	device for the ctrl device
+ * @ctrl_lock:	serialize the ioctrls.
+ */
+struct rpmsg_ctrldev {
+	struct rpmsg_device *rpdev;
+	struct cdev cdev;
+	struct device dev;
+	struct mutex ctrl_lock;
+};
+
+static int rpmsg_ctrldev_open(struct inode *inode, struct file *filp)
+{
+	struct rpmsg_ctrldev *ctrldev = cdev_to_ctrldev(inode->i_cdev);
+
+	get_device(&ctrldev->dev);
+	filp->private_data = ctrldev;
+
+	return 0;
+}
+
+static int rpmsg_ctrldev_release(struct inode *inode, struct file *filp)
+{
+	struct rpmsg_ctrldev *ctrldev = cdev_to_ctrldev(inode->i_cdev);
+
+	put_device(&ctrldev->dev);
+
+	return 0;
+}
+
+static long rpmsg_ctrldev_ioctl(struct file *fp, unsigned int cmd,
+				unsigned long arg)
+{
+	struct rpmsg_ctrldev *ctrldev = fp->private_data;
+	void __user *argp = (void __user *)arg;
+	struct rpmsg_endpoint_info eptinfo;
+	struct rpmsg_channel_info chinfo;
+	struct rpmsg_device *rpdev;
+	int ret = 0;
+
+	if (copy_from_user(&eptinfo, argp, sizeof(eptinfo)))
+		return -EFAULT;
+
+	memcpy(chinfo.name, eptinfo.name, RPMSG_NAME_SIZE);
+	chinfo.name[RPMSG_NAME_SIZE - 1] = '\0';
+	chinfo.src = eptinfo.src;
+	chinfo.dst = eptinfo.dst;
+
+	mutex_lock(&ctrldev->ctrl_lock);
+	switch (cmd) {
+	case RPMSG_CREATE_EPT_IOCTL:
+		ret = rpmsg_chrdev_eptdev_create(ctrldev->rpdev, &ctrldev->dev, chinfo);
+		break;
+
+	case RPMSG_CREATE_DEV_IOCTL:
+		rpdev = rpmsg_create_channel(ctrldev->rpdev, &chinfo);
+		if (!rpdev) {
+			dev_err(&ctrldev->dev, "failed to create %s channel\n", chinfo.name);
+			ret = -ENXIO;
+		}
+		break;
+
+	case RPMSG_RELEASE_DEV_IOCTL:
+		ret = rpmsg_release_channel(ctrldev->rpdev, &chinfo);
+		if (ret)
+			dev_err(&ctrldev->dev, "failed to release %s channel (%d)\n",
+				chinfo.name, ret);
+		break;
+
+	default:
+		ret = -EINVAL;
+	}
+	mutex_unlock(&ctrldev->ctrl_lock);
+
+	return ret;
+};
+
+static const struct file_operations rpmsg_ctrldev_fops = {
+	.owner = THIS_MODULE,
+	.open = rpmsg_ctrldev_open,
+	.release = rpmsg_ctrldev_release,
+	.unlocked_ioctl = rpmsg_ctrldev_ioctl,
+	.compat_ioctl = compat_ptr_ioctl,
+};
+
+static void rpmsg_ctrldev_release_device(struct device *dev)
+{
+	struct rpmsg_ctrldev *ctrldev = dev_to_ctrldev(dev);
+
+	ida_free(&rpmsg_ctrl_ida, dev->id);
+	ida_free(&rpmsg_minor_ida, MINOR(dev->devt));
+	kfree(ctrldev);
+}
+
+static int rpmsg_ctrldev_probe(struct rpmsg_device *rpdev)
+{
+	struct rpmsg_ctrldev *ctrldev;
+	struct device *dev;
+	int ret;
+
+	ctrldev = kzalloc_obj(*ctrldev);
+	if (!ctrldev)
+		return -ENOMEM;
+
+	ctrldev->rpdev = rpdev;
+
+	dev = &ctrldev->dev;
+	device_initialize(dev);
+	dev->parent = &rpdev->dev;
+	dev->class = &rpmsg_class;
+
+	mutex_init(&ctrldev->ctrl_lock);
+	cdev_init(&ctrldev->cdev, &rpmsg_ctrldev_fops);
+	ctrldev->cdev.owner = THIS_MODULE;
+
+	ret = ida_alloc_max(&rpmsg_minor_ida, RPMSG_DEV_MAX - 1, GFP_KERNEL);
+	if (ret < 0)
+		goto free_ctrldev;
+	dev->devt = MKDEV(MAJOR(rpmsg_major), ret);
+
+	ret = ida_alloc(&rpmsg_ctrl_ida, GFP_KERNEL);
+	if (ret < 0)
+		goto free_minor_ida;
+	dev->id = ret;
+	dev_set_name(&ctrldev->dev, "rpmsg_ctrl%d", ret);
+
+	ret = cdev_device_add(&ctrldev->cdev, &ctrldev->dev);
+	if (ret)
+		goto free_ctrl_ida;
+
+	/* We can now rely on the release function for cleanup */
+	dev->release = rpmsg_ctrldev_release_device;
+
+	dev_set_drvdata(&rpdev->dev, ctrldev);
+
+	return ret;
+
+free_ctrl_ida:
+	ida_free(&rpmsg_ctrl_ida, dev->id);
+free_minor_ida:
+	ida_free(&rpmsg_minor_ida, MINOR(dev->devt));
+free_ctrldev:
+	put_device(dev);
+	kfree(ctrldev);
+
+	return ret;
+}
+
+static void rpmsg_ctrldev_remove(struct rpmsg_device *rpdev)
+{
+	struct rpmsg_ctrldev *ctrldev = dev_get_drvdata(&rpdev->dev);
+	int ret;
+
+	mutex_lock(&ctrldev->ctrl_lock);
+	/* Destroy all endpoints */
+	ret = device_for_each_child(&ctrldev->dev, NULL, rpmsg_chrdev_eptdev_destroy);
+	if (ret)
+		dev_warn(&rpdev->dev, "failed to nuke endpoints: %d\n", ret);
+	mutex_unlock(&ctrldev->ctrl_lock);
+
+	cdev_device_del(&ctrldev->cdev, &ctrldev->dev);
+	put_device(&ctrldev->dev);
+}
+
+static struct rpmsg_driver rpmsg_ctrldev_driver = {
+	.probe = rpmsg_ctrldev_probe,
+	.remove = rpmsg_ctrldev_remove,
+	.drv = {
+		.name = "rpmsg_ctrl",
+	},
+};
+
+static int rpmsg_ctrldev_init(void)
+{
+	int ret;
+
+	ret = alloc_chrdev_region(&rpmsg_major, 0, RPMSG_DEV_MAX, "rpmsg_ctrl");
+	if (ret < 0) {
+		pr_err("failed to allocate char dev region\n");
+		return ret;
+	}
+
+	ret = register_rpmsg_driver(&rpmsg_ctrldev_driver);
+	if (ret < 0) {
+		pr_err("failed to register rpmsg driver\n");
+		unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX);
+	}
+
+	return ret;
+}
+postcore_initcall(rpmsg_ctrldev_init);
+
+static void rpmsg_ctrldev_exit(void)
+{
+	unregister_rpmsg_driver(&rpmsg_ctrldev_driver);
+	unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX);
+}
+module_exit(rpmsg_ctrldev_exit);
+
+MODULE_DESCRIPTION("rpmsg control interface");
+MODULE_ALIAS("rpmsg:" KBUILD_MODNAME);
+MODULE_LICENSE("GPL v2");