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, 445 insertions, 0 deletions

diff --git a/drivers/mtd/devices/phram.c b/drivers/mtd/devices/phram.c
new file mode 100644
index 000000000..b42cadcd7
--- /dev/null
+++ b/drivers/mtd/devices/phram.c
@@ -0,0 +1,445 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) ????		Jochen Schäuble <psionic@psionic.de>
+ * Copyright (c) 2003-2004	Joern Engel <joern@wh.fh-wedel.de>
+ *
+ * Usage:
+ *
+ * one commend line parameter per device, each in the form:
+ *   phram=<name>,<start>,<len>[,<erasesize>]
+ * <name> may be up to 63 characters.
+ * <start>, <len>, and <erasesize> can be octal, decimal or hexadecimal.  If followed
+ * by "ki", "Mi" or "Gi", the numbers will be interpreted as kilo, mega or
+ * gigabytes. <erasesize> is optional and defaults to PAGE_SIZE.
+ *
+ * Example:
+ *	phram=swap,64Mi,128Mi phram=test,900Mi,1Mi,64Ki
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/io.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/slab.h>
+#include <linux/mtd/mtd.h>
+#include <asm/div64.h>
+#include <linux/platform_device.h>
+#include <linux/of_address.h>
+#include <linux/of.h>
+#include <linux/security.h>
+
+struct phram_mtd_list {
+	struct mtd_info mtd;
+	struct list_head list;
+	bool cached;
+};
+
+static LIST_HEAD(phram_list);
+
+static int phram_erase(struct mtd_info *mtd, struct erase_info *instr)
+{
+	u_char *start = mtd->priv;
+
+	memset(start + instr->addr, 0xff, instr->len);
+
+	return 0;
+}
+
+static int phram_point(struct mtd_info *mtd, loff_t from, size_t len,
+		size_t *retlen, void **virt, resource_size_t *phys)
+{
+	*virt = mtd->priv + from;
+	*retlen = len;
+	return 0;
+}
+
+static int phram_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
+{
+	return 0;
+}
+
+static int phram_read(struct mtd_info *mtd, loff_t from, size_t len,
+		size_t *retlen, u_char *buf)
+{
+	u_char *start = mtd->priv;
+
+	memcpy(buf, start + from, len);
+	*retlen = len;
+	return 0;
+}
+
+static int phram_write(struct mtd_info *mtd, loff_t to, size_t len,
+		size_t *retlen, const u_char *buf)
+{
+	u_char *start = mtd->priv;
+
+	memcpy(start + to, buf, len);
+	*retlen = len;
+	return 0;
+}
+
+static int phram_map(struct phram_mtd_list *phram, phys_addr_t start, size_t len)
+{
+	void *addr = NULL;
+
+	if (phram->cached)
+		addr = memremap(start, len, MEMREMAP_WB);
+	else
+		addr = (void __force *)ioremap(start, len);
+	if (!addr)
+		return -EIO;
+
+	phram->mtd.priv = addr;
+
+	return 0;
+}
+
+static void phram_unmap(struct phram_mtd_list *phram)
+{
+	void *addr = phram->mtd.priv;
+
+	if (phram->cached) {
+		memunmap(addr);
+		return;
+	}
+
+	iounmap((void __iomem *)addr);
+}
+
+static void unregister_devices(void)
+{
+	struct phram_mtd_list *this, *safe;
+
+	list_for_each_entry_safe(this, safe, &phram_list, list) {
+		mtd_device_unregister(&this->mtd);
+		phram_unmap(this);
+		kfree(this->mtd.name);
+		kfree(this);
+	}
+}
+
+static int register_device(struct platform_device *pdev, const char *name,
+			   phys_addr_t start, size_t len, uint32_t erasesize)
+{
+	struct device_node *np = pdev ? pdev->dev.of_node : NULL;
+	bool cached = np ? !of_property_read_bool(np, "no-map") : false;
+	struct phram_mtd_list *new;
+	int ret = -ENOMEM;
+
+	new = kzalloc_obj(*new);
+	if (!new)
+		goto out0;
+
+	new->cached = cached;
+
+	ret = phram_map(new, start, len);
+	if (ret) {
+		pr_err("ioremap failed\n");
+		goto out1;
+	}
+
+
+	new->mtd.name = name;
+	new->mtd.size = len;
+	new->mtd.flags = MTD_CAP_RAM;
+	new->mtd._erase = phram_erase;
+	new->mtd._point = phram_point;
+	new->mtd._unpoint = phram_unpoint;
+	new->mtd._read = phram_read;
+	new->mtd._write = phram_write;
+	new->mtd.owner = THIS_MODULE;
+	new->mtd.type = MTD_RAM;
+	new->mtd.erasesize = erasesize;
+	new->mtd.writesize = 1;
+
+	mtd_set_of_node(&new->mtd, np);
+
+	ret = -EAGAIN;
+	if (mtd_device_register(&new->mtd, NULL, 0)) {
+		pr_err("Failed to register new device\n");
+		goto out2;
+	}
+
+	if (pdev)
+		platform_set_drvdata(pdev, new);
+	else
+		list_add_tail(&new->list, &phram_list);
+
+	return 0;
+
+out2:
+	phram_unmap(new);
+out1:
+	kfree(new);
+out0:
+	return ret;
+}
+
+static int parse_num64(uint64_t *num64, char *token)
+{
+	size_t len;
+	int shift = 0;
+	int ret;
+
+	len = strlen(token);
+	/* By dwmw2 editorial decree, "ki", "Mi" or "Gi" are to be used. */
+	if (len > 2) {
+		if (token[len - 1] == 'i') {
+			switch (token[len - 2]) {
+			case 'G':
+				shift += 10;
+				fallthrough;
+			case 'M':
+				shift += 10;
+				fallthrough;
+			case 'k':
+				shift += 10;
+				token[len - 2] = 0;
+				break;
+			default:
+				return -EINVAL;
+			}
+		}
+	}
+
+	ret = kstrtou64(token, 0, num64);
+	*num64 <<= shift;
+
+	return ret;
+}
+
+static int parse_name(char **pname, const char *token)
+{
+	size_t len;
+	char *name;
+
+	len = strlen(token) + 1;
+	if (len > 64)
+		return -ENOSPC;
+
+	name = kstrdup(token, GFP_KERNEL);
+	if (!name)
+		return -ENOMEM;
+
+	*pname = name;
+	return 0;
+}
+
+
+static inline void kill_final_newline(char *str)
+{
+	char *newline = strrchr(str, '\n');
+
+	if (newline && !newline[1])
+		*newline = 0;
+}
+
+
+#define parse_err(fmt, args...) do {	\
+	pr_err(fmt , ## args);	\
+	return 1;		\
+} while (0)
+
+#ifndef MODULE
+static int phram_init_called;
+/*
+ * This shall contain the module parameter if any. It is of the form:
+ * - phram=<device>,<address>,<size>[,<erasesize>] for module case
+ * - phram.phram=<device>,<address>,<size>[,<erasesize>] for built-in case
+ * We leave 64 bytes for the device name, 20 for the address , 20 for the
+ * size and 20 for the erasesize.
+ * Example: phram.phram=rootfs,0xa0000000,512Mi,65536
+ */
+static char phram_paramline[64 + 20 + 20 + 20];
+#endif
+
+static int phram_setup(const char *val)
+{
+	char buf[64 + 20 + 20 + 20], *str = buf;
+	char *token[4];
+	char *name;
+	uint64_t start;
+	uint64_t len;
+	uint64_t erasesize = PAGE_SIZE;
+	uint32_t rem;
+	int i, ret;
+
+	if (strnlen(val, sizeof(buf)) >= sizeof(buf))
+		parse_err("parameter too long\n");
+
+	strcpy(str, val);
+	kill_final_newline(str);
+
+	for (i = 0; i < 4; i++)
+		token[i] = strsep(&str, ",");
+
+	if (str)
+		parse_err("too many arguments\n");
+
+	if (!token[2])
+		parse_err("not enough arguments\n");
+
+	ret = parse_name(&name, token[0]);
+	if (ret)
+		return ret;
+
+	ret = parse_num64(&start, token[1]);
+	if (ret) {
+		parse_err("illegal start address\n");
+		goto error;
+	}
+
+	ret = parse_num64(&len, token[2]);
+	if (ret) {
+		parse_err("illegal device length\n");
+		goto error;
+	}
+
+	if (token[3]) {
+		ret = parse_num64(&erasesize, token[3]);
+		if (ret) {
+			parse_err("illegal erasesize\n");
+			goto error;
+		}
+	}
+
+	if (len == 0 || erasesize == 0 || erasesize > len
+	    || erasesize > UINT_MAX) {
+		parse_err("illegal erasesize or len\n");
+		ret = -EINVAL;
+		goto error;
+	}
+
+	div_u64_rem(len, (uint32_t)erasesize, &rem);
+	if (rem) {
+		parse_err("len is not multiple of erasesize\n");
+		ret = -EINVAL;
+		goto error;
+	}
+
+	ret = register_device(NULL, name, start, len, (uint32_t)erasesize);
+	if (ret)
+		goto error;
+
+	pr_info("%s device: %#llx at %#llx for erasesize %#llx\n", name, len, start, erasesize);
+	return 0;
+
+error:
+	kfree(name);
+	return ret;
+}
+
+static int phram_param_call(const char *val, const struct kernel_param *kp)
+{
+#ifdef MODULE
+	return phram_setup(val);
+#else
+	/*
+	 * If more parameters are later passed in via
+	 * /sys/module/phram/parameters/phram
+	 * and init_phram() has already been called,
+	 * we can parse the argument now.
+	 */
+
+	if (phram_init_called)
+		return phram_setup(val);
+
+	/*
+	 * During early boot stage, we only save the parameters
+	 * here. We must parse them later: if the param passed
+	 * from kernel boot command line, phram_param_call() is
+	 * called so early that it is not possible to resolve
+	 * the device (even kmalloc() fails). Defer that work to
+	 * phram_setup().
+	 */
+
+	if (strlen(val) >= sizeof(phram_paramline))
+		return -ENOSPC;
+	strcpy(phram_paramline, val);
+
+	return 0;
+#endif
+}
+
+module_param_call(phram, phram_param_call, NULL, NULL, 0200);
+MODULE_PARM_DESC(phram, "Memory region to map. \"phram=<name>,<start>,<length>[,<erasesize>]\"");
+
+#ifdef CONFIG_OF
+static const struct of_device_id phram_of_match[] = {
+	{ .compatible = "phram" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, phram_of_match);
+#endif
+
+static int phram_probe(struct platform_device *pdev)
+{
+	struct resource *res;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res)
+		return -ENOMEM;
+
+	/* mtd_set_of_node() reads name from "label" */
+	return register_device(pdev, NULL, res->start, resource_size(res),
+			       PAGE_SIZE);
+}
+
+static void phram_remove(struct platform_device *pdev)
+{
+	struct phram_mtd_list *phram = platform_get_drvdata(pdev);
+
+	mtd_device_unregister(&phram->mtd);
+	phram_unmap(phram);
+	kfree(phram);
+}
+
+static struct platform_driver phram_driver = {
+	.probe		= phram_probe,
+	.remove		= phram_remove,
+	.driver		= {
+		.name		= "phram",
+		.of_match_table	= of_match_ptr(phram_of_match),
+	},
+};
+
+static int __init init_phram(void)
+{
+	int ret;
+
+	ret = security_locked_down(LOCKDOWN_DEV_MEM);
+	if (ret)
+		return ret;
+
+	ret = platform_driver_register(&phram_driver);
+	if (ret)
+		return ret;
+
+#ifndef MODULE
+	if (phram_paramline[0]) {
+		ret = phram_setup(phram_paramline);
+		if (ret)
+			platform_driver_unregister(&phram_driver);
+	}
+	phram_init_called = 1;
+#endif
+
+	return ret;
+}
+
+static void __exit cleanup_phram(void)
+{
+	unregister_devices();
+	platform_driver_unregister(&phram_driver);
+}
+
+module_init(init_phram);
+module_exit(cleanup_phram);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Joern Engel <joern@wh.fh-wedel.de>");
+MODULE_DESCRIPTION("MTD driver for physical RAM");