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, 217 insertions, 0 deletions

diff --git a/drivers/input/serio/pcips2.c b/drivers/input/serio/pcips2.c
new file mode 100644
index 000000000..78f47b0ca
--- /dev/null
+++ b/drivers/input/serio/pcips2.c
@@ -0,0 +1,217 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * linux/drivers/input/serio/pcips2.c
+ *
+ *  Copyright (C) 2003 Russell King, All Rights Reserved.
+ *
+ *  I'm not sure if this is a generic PS/2 PCI interface or specific to
+ *  the Mobility Electronics docking station.
+ */
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <linux/ioport.h>
+#include <linux/input.h>
+#include <linux/pci.h>
+#include <linux/slab.h>
+#include <linux/serio.h>
+#include <linux/delay.h>
+#include <asm/io.h>
+
+#define PS2_CTRL		(0)
+#define PS2_STATUS		(1)
+#define PS2_DATA		(2)
+
+#define PS2_CTRL_CLK		(1<<0)
+#define PS2_CTRL_DAT		(1<<1)
+#define PS2_CTRL_TXIRQ		(1<<2)
+#define PS2_CTRL_ENABLE		(1<<3)
+#define PS2_CTRL_RXIRQ		(1<<4)
+
+#define PS2_STAT_CLK		(1<<0)
+#define PS2_STAT_DAT		(1<<1)
+#define PS2_STAT_PARITY		(1<<2)
+#define PS2_STAT_RXFULL		(1<<5)
+#define PS2_STAT_TXBUSY		(1<<6)
+#define PS2_STAT_TXEMPTY	(1<<7)
+
+struct pcips2_data {
+	struct serio	*io;
+	unsigned int	base;
+	struct pci_dev	*dev;
+};
+
+static int pcips2_write(struct serio *io, unsigned char val)
+{
+	struct pcips2_data *ps2if = io->port_data;
+	unsigned int stat;
+
+	do {
+		stat = inb(ps2if->base + PS2_STATUS);
+		cpu_relax();
+	} while (!(stat & PS2_STAT_TXEMPTY));
+
+	outb(val, ps2if->base + PS2_DATA);
+
+	return 0;
+}
+
+static irqreturn_t pcips2_interrupt(int irq, void *devid)
+{
+	struct pcips2_data *ps2if = devid;
+	unsigned char status, scancode;
+	int handled = 0;
+
+	do {
+		unsigned int flag;
+
+		status = inb(ps2if->base + PS2_STATUS);
+		if (!(status & PS2_STAT_RXFULL))
+			break;
+		handled = 1;
+		scancode = inb(ps2if->base + PS2_DATA);
+		if (status == 0xff && scancode == 0xff)
+			break;
+
+		flag = (status & PS2_STAT_PARITY) ? 0 : SERIO_PARITY;
+
+		if (hweight8(scancode) & 1)
+			flag ^= SERIO_PARITY;
+
+		serio_interrupt(ps2if->io, scancode, flag);
+	} while (1);
+	return IRQ_RETVAL(handled);
+}
+
+static void pcips2_flush_input(struct pcips2_data *ps2if)
+{
+	unsigned char status, scancode;
+
+	do {
+		status = inb(ps2if->base + PS2_STATUS);
+		if (!(status & PS2_STAT_RXFULL))
+			break;
+		scancode = inb(ps2if->base + PS2_DATA);
+		if (status == 0xff && scancode == 0xff)
+			break;
+	} while (1);
+}
+
+static int pcips2_open(struct serio *io)
+{
+	struct pcips2_data *ps2if = io->port_data;
+	int ret, val = 0;
+
+	outb(PS2_CTRL_ENABLE, ps2if->base);
+	pcips2_flush_input(ps2if);
+
+	ret = request_irq(ps2if->dev->irq, pcips2_interrupt, IRQF_SHARED,
+			  "pcips2", ps2if);
+	if (ret == 0)
+		val = PS2_CTRL_ENABLE | PS2_CTRL_RXIRQ;
+
+	outb(val, ps2if->base);
+
+	return ret;
+}
+
+static void pcips2_close(struct serio *io)
+{
+	struct pcips2_data *ps2if = io->port_data;
+
+	outb(0, ps2if->base);
+
+	free_irq(ps2if->dev->irq, ps2if);
+}
+
+static int pcips2_probe(struct pci_dev *dev, const struct pci_device_id *id)
+{
+	struct pcips2_data *ps2if;
+	struct serio *serio;
+	int ret;
+
+	ret = pci_enable_device(dev);
+	if (ret)
+		goto out;
+
+	ret = pci_request_regions(dev, "pcips2");
+	if (ret)
+		goto disable;
+
+	ps2if = kzalloc_obj(*ps2if);
+	serio = kzalloc_obj(*serio);
+	if (!ps2if || !serio) {
+		ret = -ENOMEM;
+		goto release;
+	}
+
+
+	serio->id.type		= SERIO_8042;
+	serio->write		= pcips2_write;
+	serio->open		= pcips2_open;
+	serio->close		= pcips2_close;
+	strscpy(serio->name, pci_name(dev), sizeof(serio->name));
+	strscpy(serio->phys, dev_name(&dev->dev), sizeof(serio->phys));
+	serio->port_data	= ps2if;
+	serio->dev.parent	= &dev->dev;
+	ps2if->io		= serio;
+	ps2if->dev		= dev;
+	ps2if->base		= pci_resource_start(dev, 0);
+
+	pci_set_drvdata(dev, ps2if);
+
+	serio_register_port(ps2if->io);
+	return 0;
+
+ release:
+	kfree(ps2if);
+	kfree(serio);
+	pci_release_regions(dev);
+ disable:
+	pci_disable_device(dev);
+ out:
+	return ret;
+}
+
+static void pcips2_remove(struct pci_dev *dev)
+{
+	struct pcips2_data *ps2if = pci_get_drvdata(dev);
+
+	serio_unregister_port(ps2if->io);
+	kfree(ps2if);
+	pci_release_regions(dev);
+	pci_disable_device(dev);
+}
+
+static const struct pci_device_id pcips2_ids[] = {
+	{
+		.vendor		= 0x14f2,	/* MOBILITY */
+		.device		= 0x0123,	/* Keyboard */
+		.subvendor	= PCI_ANY_ID,
+		.subdevice	= PCI_ANY_ID,
+		.class		= PCI_CLASS_INPUT_KEYBOARD << 8,
+		.class_mask	= 0xffff00,
+	},
+	{
+		.vendor		= 0x14f2,	/* MOBILITY */
+		.device		= 0x0124,	/* Mouse */
+		.subvendor	= PCI_ANY_ID,
+		.subdevice	= PCI_ANY_ID,
+		.class		= PCI_CLASS_INPUT_MOUSE << 8,
+		.class_mask	= 0xffff00,
+	},
+	{ 0, }
+};
+MODULE_DEVICE_TABLE(pci, pcips2_ids);
+
+static struct pci_driver pcips2_driver = {
+	.name			= "pcips2",
+	.id_table		= pcips2_ids,
+	.probe			= pcips2_probe,
+	.remove			= pcips2_remove,
+};
+
+module_pci_driver(pcips2_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>");
+MODULE_DESCRIPTION("PCI PS/2 keyboard/mouse driver");