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, 320 insertions, 0 deletions

diff --git a/drivers/input/mouse/psmouse-smbus.c b/drivers/input/mouse/psmouse-smbus.c
new file mode 100644
index 000000000..98d9c860d
--- /dev/null
+++ b/drivers/input/mouse/psmouse-smbus.c
@@ -0,0 +1,320 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2017 Red Hat, Inc
+ */
+
+#define pr_fmt(fmt)		KBUILD_MODNAME ": " fmt
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/libps2.h>
+#include <linux/i2c.h>
+#include <linux/serio.h>
+#include <linux/slab.h>
+#include <linux/workqueue.h>
+#include "psmouse.h"
+
+struct psmouse_smbus_dev {
+	struct i2c_board_info board;
+	struct psmouse *psmouse;
+	struct i2c_client *client;
+	struct list_head node;
+	bool dead;
+	bool need_deactivate;
+};
+
+static LIST_HEAD(psmouse_smbus_list);
+static DEFINE_MUTEX(psmouse_smbus_mutex);
+
+static struct workqueue_struct *psmouse_smbus_wq;
+
+static void psmouse_smbus_check_adapter(struct i2c_adapter *adapter)
+{
+	struct psmouse_smbus_dev *smbdev;
+
+	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_HOST_NOTIFY))
+		return;
+
+	guard(mutex)(&psmouse_smbus_mutex);
+
+	list_for_each_entry(smbdev, &psmouse_smbus_list, node) {
+		if (smbdev->dead)
+			continue;
+
+		if (smbdev->client)
+			continue;
+
+		/*
+		 * Here would be a good place to check if device is actually
+		 * present, but it seems that SMBus will not respond unless we
+		 * fully reset PS/2 connection.  So cross our fingers, and try
+		 * to switch over, hopefully our system will not have too many
+		 * "host notify" I2C adapters.
+		 */
+		psmouse_dbg(smbdev->psmouse,
+			    "SMBus candidate adapter appeared, triggering rescan\n");
+		serio_rescan(smbdev->psmouse->ps2dev.serio);
+	}
+}
+
+static void psmouse_smbus_detach_i2c_client(struct i2c_client *client)
+{
+	struct psmouse_smbus_dev *smbdev, *tmp;
+
+	guard(mutex)(&psmouse_smbus_mutex);
+
+	list_for_each_entry_safe(smbdev, tmp, &psmouse_smbus_list, node) {
+		if (smbdev->client != client)
+			continue;
+
+		kfree(client->dev.platform_data);
+		client->dev.platform_data = NULL;
+
+		if (!smbdev->dead) {
+			psmouse_dbg(smbdev->psmouse,
+				    "Marking SMBus companion %s as gone\n",
+				    dev_name(&smbdev->client->dev));
+			smbdev->dead = true;
+			device_link_remove(&smbdev->client->dev,
+					   &smbdev->psmouse->ps2dev.serio->dev);
+			serio_rescan(smbdev->psmouse->ps2dev.serio);
+		} else {
+			list_del(&smbdev->node);
+			kfree(smbdev);
+		}
+	}
+}
+
+static int psmouse_smbus_notifier_call(struct notifier_block *nb,
+				       unsigned long action, void *data)
+{
+	struct device *dev = data;
+
+	switch (action) {
+	case BUS_NOTIFY_ADD_DEVICE:
+		if (dev->type == &i2c_adapter_type)
+			psmouse_smbus_check_adapter(to_i2c_adapter(dev));
+		break;
+
+	case BUS_NOTIFY_REMOVED_DEVICE:
+		if (dev->type == &i2c_client_type)
+			psmouse_smbus_detach_i2c_client(to_i2c_client(dev));
+		break;
+	}
+
+	return 0;
+}
+
+static struct notifier_block psmouse_smbus_notifier = {
+	.notifier_call = psmouse_smbus_notifier_call,
+};
+
+static psmouse_ret_t psmouse_smbus_process_byte(struct psmouse *psmouse)
+{
+	return PSMOUSE_FULL_PACKET;
+}
+
+static int psmouse_smbus_reconnect(struct psmouse *psmouse)
+{
+	struct psmouse_smbus_dev *smbdev = psmouse->private;
+
+	if (smbdev->need_deactivate)
+		psmouse_deactivate(psmouse);
+
+	return 0;
+}
+
+struct psmouse_smbus_removal_work {
+	struct work_struct work;
+	struct i2c_client *client;
+};
+
+static void psmouse_smbus_remove_i2c_device(struct work_struct *work)
+{
+	struct psmouse_smbus_removal_work *rwork =
+		container_of(work, struct psmouse_smbus_removal_work, work);
+
+	dev_dbg(&rwork->client->dev, "destroying SMBus companion device\n");
+	i2c_unregister_device(rwork->client);
+
+	kfree(rwork);
+}
+
+/*
+ * This schedules removal of SMBus companion device. We have to do
+ * it in a separate tread to avoid deadlocking on psmouse_mutex in
+ * case the device has a trackstick (which is also driven by psmouse).
+ *
+ * Note that this may be racing with i2c adapter removal, but we
+ * can't do anything about that: i2c automatically destroys clients
+ * attached to an adapter that is being removed. This has to be
+ * fixed in i2c core.
+ */
+static void psmouse_smbus_schedule_remove(struct i2c_client *client)
+{
+	struct psmouse_smbus_removal_work *rwork;
+
+	rwork = kzalloc_obj(*rwork);
+	if (rwork) {
+		INIT_WORK(&rwork->work, psmouse_smbus_remove_i2c_device);
+		rwork->client = client;
+
+		queue_work(psmouse_smbus_wq, &rwork->work);
+	}
+}
+
+static void psmouse_smbus_disconnect(struct psmouse *psmouse)
+{
+	struct psmouse_smbus_dev *smbdev = psmouse->private;
+
+	guard(mutex)(&psmouse_smbus_mutex);
+
+	if (smbdev->dead) {
+		list_del(&smbdev->node);
+		kfree(smbdev);
+	} else {
+		smbdev->dead = true;
+		device_link_remove(&smbdev->client->dev,
+				   &psmouse->ps2dev.serio->dev);
+		psmouse_dbg(smbdev->psmouse,
+			    "posting removal request for SMBus companion %s\n",
+			    dev_name(&smbdev->client->dev));
+		psmouse_smbus_schedule_remove(smbdev->client);
+	}
+
+	psmouse->private = NULL;
+}
+
+static int psmouse_smbus_create_companion(struct device *dev, void *data)
+{
+	struct psmouse_smbus_dev *smbdev = data;
+	unsigned short addr_list[] = { smbdev->board.addr, I2C_CLIENT_END };
+	struct i2c_adapter *adapter;
+	struct i2c_client *client;
+
+	adapter = i2c_verify_adapter(dev);
+	if (!adapter)
+		return 0;
+
+	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_HOST_NOTIFY))
+		return 0;
+
+	client = i2c_new_scanned_device(adapter, &smbdev->board,
+					addr_list, NULL);
+	if (IS_ERR(client))
+		return 0;
+
+	/* We have our(?) device, stop iterating i2c bus. */
+	smbdev->client = client;
+	return 1;
+}
+
+void psmouse_smbus_cleanup(struct psmouse *psmouse)
+{
+	struct psmouse_smbus_dev *smbdev, *tmp;
+
+	guard(mutex)(&psmouse_smbus_mutex);
+
+	list_for_each_entry_safe(smbdev, tmp, &psmouse_smbus_list, node) {
+		if (psmouse == smbdev->psmouse) {
+			list_del(&smbdev->node);
+			kfree(smbdev);
+		}
+	}
+}
+
+int psmouse_smbus_init(struct psmouse *psmouse,
+		       const struct i2c_board_info *board,
+		       const void *pdata, size_t pdata_size,
+		       bool need_deactivate,
+		       bool leave_breadcrumbs)
+{
+	struct psmouse_smbus_dev *smbdev;
+	int error;
+
+	smbdev = kzalloc_obj(*smbdev);
+	if (!smbdev)
+		return -ENOMEM;
+
+	smbdev->psmouse = psmouse;
+	smbdev->board = *board;
+	smbdev->need_deactivate = need_deactivate;
+
+	if (pdata) {
+		smbdev->board.platform_data = kmemdup(pdata, pdata_size,
+						      GFP_KERNEL);
+		if (!smbdev->board.platform_data) {
+			kfree(smbdev);
+			return -ENOMEM;
+		}
+	}
+
+	if (need_deactivate)
+		psmouse_deactivate(psmouse);
+
+	psmouse->private = smbdev;
+	psmouse->protocol_handler = psmouse_smbus_process_byte;
+	psmouse->reconnect = psmouse_smbus_reconnect;
+	psmouse->fast_reconnect = psmouse_smbus_reconnect;
+	psmouse->disconnect = psmouse_smbus_disconnect;
+	psmouse->resync_time = 0;
+
+	scoped_guard(mutex, &psmouse_smbus_mutex) {
+		list_add_tail(&smbdev->node, &psmouse_smbus_list);
+	}
+
+	/* Bind to already existing adapters right away */
+	error = i2c_for_each_dev(smbdev, psmouse_smbus_create_companion);
+
+	if (smbdev->client) {
+		/* We have our companion device */
+		if (!device_link_add(&smbdev->client->dev,
+				     &psmouse->ps2dev.serio->dev,
+				     DL_FLAG_STATELESS))
+			psmouse_warn(psmouse,
+				     "failed to set up link with iSMBus companion %s\n",
+				     dev_name(&smbdev->client->dev));
+		return 0;
+	}
+
+	/*
+	 * If we did not create i2c device we will not need platform
+	 * data even if we are leaving breadcrumbs.
+	 */
+	kfree(smbdev->board.platform_data);
+	smbdev->board.platform_data = NULL;
+
+	if (error < 0 || !leave_breadcrumbs) {
+		scoped_guard(mutex, &psmouse_smbus_mutex) {
+			list_del(&smbdev->node);
+		}
+
+		kfree(smbdev);
+	}
+
+	return error < 0 ? error : -EAGAIN;
+}
+
+int __init psmouse_smbus_module_init(void)
+{
+	int error;
+
+	psmouse_smbus_wq = alloc_workqueue("psmouse-smbus", WQ_UNBOUND, 0);
+	if (!psmouse_smbus_wq)
+		return -ENOMEM;
+
+	error = bus_register_notifier(&i2c_bus_type, &psmouse_smbus_notifier);
+	if (error) {
+		pr_err("failed to register i2c bus notifier: %d\n", error);
+		destroy_workqueue(psmouse_smbus_wq);
+		return error;
+	}
+
+	return 0;
+}
+
+void psmouse_smbus_module_exit(void)
+{
+	bus_unregister_notifier(&i2c_bus_type, &psmouse_smbus_notifier);
+	destroy_workqueue(psmouse_smbus_wq);
+}