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, 195 insertions, 0 deletions

diff --git a/drivers/misc/mei/debugfs.c b/drivers/misc/mei/debugfs.c
new file mode 100644
index 000000000..3b098d4c8
--- /dev/null
+++ b/drivers/misc/mei/debugfs.c
@@ -0,0 +1,195 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2012-2022, Intel Corporation. All rights reserved
+ * Intel Management Engine Interface (Intel MEI) Linux driver
+ */
+
+#include <linux/slab.h>
+#include <linux/kernel.h>
+#include <linux/device.h>
+#include <linux/debugfs.h>
+#include <linux/seq_file.h>
+
+#include <linux/mei.h>
+
+#include "mei_dev.h"
+#include "client.h"
+#include "hw.h"
+
+static int mei_dbgfs_meclients_show(struct seq_file *m, void *unused)
+{
+	struct mei_device *dev = m->private;
+	struct mei_me_client *me_cl;
+	int i = 0;
+
+	if (!dev)
+		return -ENODEV;
+
+	down_read(&dev->me_clients_rwsem);
+
+	seq_puts(m, "  |id|fix|         UUID                       |con|msg len|sb|refc|vt|\n");
+
+	/*  if the driver is not enabled the list won't be consistent */
+	if (dev->dev_state != MEI_DEV_ENABLED)
+		goto out;
+
+	list_for_each_entry(me_cl, &dev->me_clients, list) {
+		if (!mei_me_cl_get(me_cl))
+			continue;
+
+		seq_printf(m, "%2d|%2d|%3d|%pUl|%3d|%7d|%2d|%4d|%2d|\n",
+			   i++, me_cl->client_id,
+			   me_cl->props.fixed_address,
+			   &me_cl->props.protocol_name,
+			   me_cl->props.max_number_of_connections,
+			   me_cl->props.max_msg_length,
+			   me_cl->props.single_recv_buf,
+			   kref_read(&me_cl->refcnt),
+			   me_cl->props.vt_supported);
+		mei_me_cl_put(me_cl);
+	}
+
+out:
+	up_read(&dev->me_clients_rwsem);
+	return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(mei_dbgfs_meclients);
+
+static int mei_dbgfs_active_show(struct seq_file *m, void *unused)
+{
+	struct mei_device *dev = m->private;
+	struct mei_cl *cl;
+	int i = 0;
+
+	if (!dev)
+		return -ENODEV;
+
+	mutex_lock(&dev->device_lock);
+
+	seq_puts(m, "   |me|host|state|rd|wr|wrq\n");
+
+	/*  if the driver is not enabled the list won't be consistent */
+	if (dev->dev_state != MEI_DEV_ENABLED)
+		goto out;
+
+	list_for_each_entry(cl, &dev->file_list, link) {
+
+		seq_printf(m, "%3d|%2d|%4d|%5d|%2d|%2d|%3u\n",
+			   i, mei_cl_me_id(cl), cl->host_client_id, cl->state,
+			   !list_empty(&cl->rd_completed), cl->writing_state,
+			   cl->tx_cb_queued);
+		i++;
+	}
+out:
+	mutex_unlock(&dev->device_lock);
+	return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(mei_dbgfs_active);
+
+static const char *mei_dev_pxp_mode_str(enum mei_dev_pxp_mode state)
+{
+#define MEI_PXP_MODE(state) case MEI_DEV_PXP_##state: return #state
+	switch (state) {
+	MEI_PXP_MODE(DEFAULT);
+	MEI_PXP_MODE(INIT);
+	MEI_PXP_MODE(SETUP);
+	MEI_PXP_MODE(READY);
+	default:
+		return "unknown";
+	}
+#undef MEI_PXP_MODE
+}
+
+static int mei_dbgfs_devstate_show(struct seq_file *m, void *unused)
+{
+	struct mei_device *dev = m->private;
+
+	seq_printf(m, "dev: %s\n", mei_dev_state_str(dev->dev_state));
+	seq_printf(m, "hbm: %s\n", mei_hbm_state_str(dev->hbm_state));
+
+	if (dev->hbm_state >= MEI_HBM_ENUM_CLIENTS &&
+	    dev->hbm_state <= MEI_HBM_STARTED) {
+		seq_puts(m, "hbm features:\n");
+		seq_printf(m, "\tPG: %01d\n", dev->hbm_f_pg_supported);
+		seq_printf(m, "\tDC: %01d\n", dev->hbm_f_dc_supported);
+		seq_printf(m, "\tIE: %01d\n", dev->hbm_f_ie_supported);
+		seq_printf(m, "\tDOT: %01d\n", dev->hbm_f_dot_supported);
+		seq_printf(m, "\tEV: %01d\n", dev->hbm_f_ev_supported);
+		seq_printf(m, "\tFA: %01d\n", dev->hbm_f_fa_supported);
+		seq_printf(m, "\tOS: %01d\n", dev->hbm_f_os_supported);
+		seq_printf(m, "\tDR: %01d\n", dev->hbm_f_dr_supported);
+		seq_printf(m, "\tVT: %01d\n", dev->hbm_f_vt_supported);
+		seq_printf(m, "\tCAP: %01d\n", dev->hbm_f_cap_supported);
+		seq_printf(m, "\tCD: %01d\n", dev->hbm_f_cd_supported);
+	}
+
+	seq_printf(m, "pg:  %s, %s\n",
+		   mei_pg_is_enabled(dev) ? "ENABLED" : "DISABLED",
+		   mei_pg_state_str(mei_pg_state(dev)));
+
+	seq_printf(m, "pxp: %s\n", mei_dev_pxp_mode_str(dev->pxp_mode));
+
+	return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(mei_dbgfs_devstate);
+
+static ssize_t mei_dbgfs_write_allow_fa(struct file *file,
+					const char __user *user_buf,
+					size_t count, loff_t *ppos)
+{
+	struct mei_device *dev;
+	int ret;
+
+	dev = container_of(file->private_data,
+			   struct mei_device, allow_fixed_address);
+
+	ret = debugfs_write_file_bool(file, user_buf, count, ppos);
+	if (ret < 0)
+		return ret;
+	dev->override_fixed_address = true;
+	return ret;
+}
+
+static const struct file_operations mei_dbgfs_allow_fa_fops = {
+	.open = simple_open,
+	.read = debugfs_read_file_bool,
+	.write = mei_dbgfs_write_allow_fa,
+	.llseek = generic_file_llseek,
+};
+
+/**
+ * mei_dbgfs_deregister - Remove the debugfs files and directories
+ *
+ * @dev: the mei device structure
+ */
+void mei_dbgfs_deregister(struct mei_device *dev)
+{
+	if (!dev->dbgfs_dir)
+		return;
+	debugfs_remove_recursive(dev->dbgfs_dir);
+	dev->dbgfs_dir = NULL;
+}
+
+/**
+ * mei_dbgfs_register - Add the debugfs files
+ *
+ * @dev: the mei device structure
+ * @name: the mei device name
+ */
+void mei_dbgfs_register(struct mei_device *dev, const char *name)
+{
+	struct dentry *dir;
+
+	dir = debugfs_create_dir(name, NULL);
+	dev->dbgfs_dir = dir;
+
+	debugfs_create_file("meclients", S_IRUSR, dir, dev,
+			    &mei_dbgfs_meclients_fops);
+	debugfs_create_file("active", S_IRUSR, dir, dev,
+			    &mei_dbgfs_active_fops);
+	debugfs_create_file("devstate", S_IRUSR, dir, dev,
+			    &mei_dbgfs_devstate_fops);
+	debugfs_create_file("allow_fixed_address", S_IRUSR | S_IWUSR, dir,
+			    &dev->allow_fixed_address,
+			    &mei_dbgfs_allow_fa_fops);
+}