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, 213 insertions, 0 deletions

diff --git a/drivers/acpi/nvs.c b/drivers/acpi/nvs.c
new file mode 100644
index 000000000..12aee4102
--- /dev/null
+++ b/drivers/acpi/nvs.c
@@ -0,0 +1,213 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * nvs.c - Routines for saving and restoring ACPI NVS memory region
+ *
+ * Copyright (C) 2008-2011 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc.
+ */
+
+#define pr_fmt(fmt) "ACPI: PM: " fmt
+
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/acpi.h>
+
+#include "internal.h"
+
+/* ACPI NVS regions, APEI may use it */
+
+struct nvs_region {
+	__u64 phys_start;
+	__u64 size;
+	struct list_head node;
+};
+
+static LIST_HEAD(nvs_region_list);
+
+#ifdef CONFIG_ACPI_SLEEP
+static int suspend_nvs_register(unsigned long start, unsigned long size);
+#else
+static inline int suspend_nvs_register(unsigned long a, unsigned long b)
+{
+	return 0;
+}
+#endif
+
+int acpi_nvs_register(__u64 start, __u64 size)
+{
+	struct nvs_region *region;
+
+	region = kmalloc_obj(*region);
+	if (!region)
+		return -ENOMEM;
+	region->phys_start = start;
+	region->size = size;
+	list_add_tail(&region->node, &nvs_region_list);
+
+	return suspend_nvs_register(start, size);
+}
+
+int acpi_nvs_for_each_region(int (*func)(__u64 start, __u64 size, void *data),
+			     void *data)
+{
+	int rc;
+	struct nvs_region *region;
+
+	list_for_each_entry(region, &nvs_region_list, node) {
+		rc = func(region->phys_start, region->size, data);
+		if (rc)
+			return rc;
+	}
+
+	return 0;
+}
+
+
+#ifdef CONFIG_ACPI_SLEEP
+/*
+ * Platforms, like ACPI, may want us to save some memory used by them during
+ * suspend and to restore the contents of this memory during the subsequent
+ * resume.  The code below implements a mechanism allowing us to do that.
+ */
+
+struct nvs_page {
+	unsigned long phys_start;
+	unsigned int size;
+	void *kaddr;
+	void *data;
+	bool unmap;
+	struct list_head node;
+};
+
+static LIST_HEAD(nvs_list);
+
+/**
+ * suspend_nvs_register - register platform NVS memory region to save
+ * @start: Physical address of the region.
+ * @size: Size of the region.
+ *
+ * The NVS region need not be page-aligned (both ends) and we arrange
+ * things so that the data from page-aligned addresses in this region will
+ * be copied into separate RAM pages.
+ */
+static int suspend_nvs_register(unsigned long start, unsigned long size)
+{
+	struct nvs_page *entry, *next;
+
+	pr_info("Registering ACPI NVS region [mem %#010lx-%#010lx] (%ld bytes)\n",
+		start, start + size - 1, size);
+
+	while (size > 0) {
+		unsigned int nr_bytes;
+
+		entry = kzalloc_obj(struct nvs_page);
+		if (!entry)
+			goto Error;
+
+		list_add_tail(&entry->node, &nvs_list);
+		entry->phys_start = start;
+		nr_bytes = PAGE_SIZE - (start & ~PAGE_MASK);
+		entry->size = (size < nr_bytes) ? size : nr_bytes;
+
+		start += entry->size;
+		size -= entry->size;
+	}
+	return 0;
+
+ Error:
+	list_for_each_entry_safe(entry, next, &nvs_list, node) {
+		list_del(&entry->node);
+		kfree(entry);
+	}
+	return -ENOMEM;
+}
+
+/**
+ * suspend_nvs_free - free data pages allocated for saving NVS regions
+ */
+void suspend_nvs_free(void)
+{
+	struct nvs_page *entry;
+
+	list_for_each_entry(entry, &nvs_list, node)
+		if (entry->data) {
+			kfree(entry->data);
+			entry->data = NULL;
+			if (entry->kaddr) {
+				if (entry->unmap) {
+					iounmap(entry->kaddr);
+					entry->unmap = false;
+				} else {
+					acpi_os_unmap_iomem(entry->kaddr,
+							    entry->size);
+				}
+				entry->kaddr = NULL;
+			}
+		}
+}
+
+/**
+ * suspend_nvs_alloc - allocate memory necessary for saving NVS regions
+ */
+int suspend_nvs_alloc(void)
+{
+	struct nvs_page *entry;
+
+	list_for_each_entry(entry, &nvs_list, node) {
+		entry->data = kmalloc(PAGE_SIZE, GFP_KERNEL);
+		if (!entry->data) {
+			suspend_nvs_free();
+			return -ENOMEM;
+		}
+	}
+	return 0;
+}
+
+/**
+ * suspend_nvs_save - save NVS memory regions
+ */
+int suspend_nvs_save(void)
+{
+	struct nvs_page *entry;
+
+	pr_info("Saving platform NVS memory\n");
+
+	list_for_each_entry(entry, &nvs_list, node)
+		if (entry->data) {
+			unsigned long phys = entry->phys_start;
+			unsigned int size = entry->size;
+
+			entry->kaddr = acpi_os_get_iomem(phys, size);
+			if (!entry->kaddr) {
+				entry->kaddr = acpi_os_ioremap(phys, size);
+				entry->unmap = !!entry->kaddr;
+			}
+			if (!entry->kaddr) {
+				suspend_nvs_free();
+				return -ENOMEM;
+			}
+			memcpy(entry->data, entry->kaddr, entry->size);
+		}
+
+	return 0;
+}
+
+/**
+ * suspend_nvs_restore - restore NVS memory regions
+ *
+ * This function is going to be called with interrupts disabled, so it
+ * cannot iounmap the virtual addresses used to access the NVS region.
+ */
+void suspend_nvs_restore(void)
+{
+	struct nvs_page *entry;
+
+	pr_info("Restoring platform NVS memory\n");
+
+	list_for_each_entry(entry, &nvs_list, node)
+		if (entry->data)
+			memcpy(entry->kaddr, entry->data, entry->size);
+}
+#endif