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, 153 insertions, 0 deletions

diff --git a/drivers/input/mouse/maplemouse.c b/drivers/input/mouse/maplemouse.c
new file mode 100644
index 000000000..0c8f7d1b0
--- /dev/null
+++ b/drivers/input/mouse/maplemouse.c
@@ -0,0 +1,153 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *	SEGA Dreamcast mouse driver
+ *	Based on drivers/usb/usbmouse.c
+ *
+ *	Copyright (c) Yaegashi Takeshi, 2001
+ *	Copyright (c) Adrian McMenamin, 2008 - 2009
+ */
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/input.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/timer.h>
+#include <linux/maple.h>
+
+MODULE_AUTHOR("Adrian McMenamin <adrian@mcmen.demon.co.uk>");
+MODULE_DESCRIPTION("SEGA Dreamcast mouse driver");
+MODULE_LICENSE("GPL");
+
+struct dc_mouse {
+	struct input_dev *dev;
+	struct maple_device *mdev;
+};
+
+static void dc_mouse_callback(struct mapleq *mq)
+{
+	int buttons, relx, rely, relz;
+	struct maple_device *mapledev = mq->dev;
+	struct dc_mouse *mse = maple_get_drvdata(mapledev);
+	struct input_dev *dev = mse->dev;
+	unsigned char *res = mq->recvbuf->buf;
+
+	buttons = ~res[8];
+	relx = *(unsigned short *)(res + 12) - 512;
+	rely = *(unsigned short *)(res + 14) - 512;
+	relz = *(unsigned short *)(res + 16) - 512;
+
+	input_report_key(dev, BTN_LEFT,   buttons & 4);
+	input_report_key(dev, BTN_MIDDLE, buttons & 9);
+	input_report_key(dev, BTN_RIGHT,  buttons & 2);
+	input_report_rel(dev, REL_X,      relx);
+	input_report_rel(dev, REL_Y,      rely);
+	input_report_rel(dev, REL_WHEEL,  relz);
+	input_sync(dev);
+}
+
+static int dc_mouse_open(struct input_dev *dev)
+{
+	struct dc_mouse *mse = input_get_drvdata(dev);
+
+	maple_getcond_callback(mse->mdev, dc_mouse_callback, HZ/50,
+		MAPLE_FUNC_MOUSE);
+
+	return 0;
+}
+
+static void dc_mouse_close(struct input_dev *dev)
+{
+	struct dc_mouse *mse = input_get_drvdata(dev);
+
+	maple_getcond_callback(mse->mdev, dc_mouse_callback, 0,
+		MAPLE_FUNC_MOUSE);
+}
+
+/* allow the mouse to be used */
+static int probe_maple_mouse(struct device *dev)
+{
+	struct maple_device *mdev = to_maple_dev(dev);
+	struct maple_driver *mdrv = to_maple_driver(dev->driver);
+	int error;
+	struct input_dev *input_dev;
+	struct dc_mouse *mse;
+
+	mse = kzalloc_obj(*mse);
+	if (!mse) {
+		error = -ENOMEM;
+		goto fail;
+	}
+
+	input_dev = input_allocate_device();
+	if (!input_dev) {
+		error = -ENOMEM;
+		goto fail_nomem;
+	}
+
+	mse->dev = input_dev;
+	mse->mdev = mdev;
+
+	maple_set_drvdata(mdev, mse);
+
+	input_set_drvdata(input_dev, mse);
+	input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_REL);
+	input_dev->keybit[BIT_WORD(BTN_MOUSE)] = BIT_MASK(BTN_LEFT) |
+		BIT_MASK(BTN_RIGHT) | BIT_MASK(BTN_MIDDLE);
+	input_dev->relbit[0] = BIT_MASK(REL_X) | BIT_MASK(REL_Y) |
+		BIT_MASK(REL_WHEEL);
+	input_dev->open = dc_mouse_open;
+	input_dev->close = dc_mouse_close;
+	input_dev->name = mdev->product_name;
+	input_dev->id.bustype = BUS_HOST;
+	error =	input_register_device(input_dev);
+	if (error)
+		goto fail_register;
+
+	mdev->driver = mdrv;
+
+	return error;
+
+fail_register:
+	input_free_device(input_dev);
+	maple_set_drvdata(mdev, NULL);
+fail_nomem:
+	kfree(mse);
+fail:
+	return error;
+}
+
+static int remove_maple_mouse(struct device *dev)
+{
+	struct maple_device *mdev = to_maple_dev(dev);
+	struct dc_mouse *mse = maple_get_drvdata(mdev);
+
+	mdev->callback = NULL;
+	input_unregister_device(mse->dev);
+	maple_set_drvdata(mdev, NULL);
+	kfree(mse);
+
+	return 0;
+}
+
+static struct maple_driver dc_mouse_driver = {
+	.function =	MAPLE_FUNC_MOUSE,
+	.drv = {
+		.name = "Dreamcast_mouse",
+		.probe = probe_maple_mouse,
+		.remove = remove_maple_mouse,
+	},
+};
+
+static int __init dc_mouse_init(void)
+{
+	return maple_driver_register(&dc_mouse_driver);
+}
+
+static void __exit dc_mouse_exit(void)
+{
+	maple_driver_unregister(&dc_mouse_driver);
+}
+
+module_init(dc_mouse_init);
+module_exit(dc_mouse_exit);