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, 130 insertions, 0 deletions

diff --git a/drivers/ssb/pcihost_wrapper.c b/drivers/ssb/pcihost_wrapper.c
new file mode 100644
index 000000000..5b6b5e0e4
--- /dev/null
+++ b/drivers/ssb/pcihost_wrapper.c
@@ -0,0 +1,130 @@
+/*
+ * Sonics Silicon Backplane
+ * PCI Hostdevice wrapper
+ *
+ * Copyright (c) 2005 Martin Langer <martin-langer@gmx.de>
+ * Copyright (c) 2005 Stefano Brivio <st3@riseup.net>
+ * Copyright (c) 2005 Danny van Dyk <kugelfang@gentoo.org>
+ * Copyright (c) 2005 Andreas Jaggi <andreas.jaggi@waterwave.ch>
+ * Copyright (c) 2005-2007 Michael Buesch <m@bues.ch>
+ *
+ * Licensed under the GNU/GPL. See COPYING for details.
+ */
+
+#include <linux/pm.h>
+#include <linux/pci.h>
+#include <linux/export.h>
+#include <linux/slab.h>
+#include <linux/ssb/ssb.h>
+
+
+#ifdef CONFIG_PM_SLEEP
+static int ssb_pcihost_suspend(struct device *d)
+{
+	struct pci_dev *dev = to_pci_dev(d);
+	struct ssb_bus *ssb = pci_get_drvdata(dev);
+	int err;
+
+	err = ssb_bus_suspend(ssb);
+	if (err)
+		return err;
+	pci_save_state(dev);
+	pci_disable_device(dev);
+
+	/* if there is a wakeup enabled child device on ssb bus,
+	   enable pci wakeup posibility. */
+	device_set_wakeup_enable(d, d->power.wakeup_path);
+
+	pci_prepare_to_sleep(dev);
+
+	return 0;
+}
+
+static int ssb_pcihost_resume(struct device *d)
+{
+	struct pci_dev *dev = to_pci_dev(d);
+	struct ssb_bus *ssb = pci_get_drvdata(dev);
+	int err;
+
+	pci_back_from_sleep(dev);
+	err = pci_enable_device(dev);
+	if (err)
+		return err;
+	pci_restore_state(dev);
+	err = ssb_bus_resume(ssb);
+	if (err)
+		return err;
+
+	return 0;
+}
+
+static const struct dev_pm_ops ssb_pcihost_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(ssb_pcihost_suspend, ssb_pcihost_resume)
+};
+
+#endif /* CONFIG_PM_SLEEP */
+
+static int ssb_pcihost_probe(struct pci_dev *dev,
+			     const struct pci_device_id *id)
+{
+	struct ssb_bus *ssb;
+	int err = -ENOMEM;
+	u32 val;
+
+	ssb = kzalloc_obj(*ssb);
+	if (!ssb)
+		goto out;
+	err = pci_enable_device(dev);
+	if (err)
+		goto err_kfree_ssb;
+	err = pci_request_regions(dev, dev_driver_string(&dev->dev));
+	if (err)
+		goto err_pci_disable;
+	pci_set_master(dev);
+
+	/* Disable the RETRY_TIMEOUT register (0x41) to keep
+	 * PCI Tx retries from interfering with C3 CPU state */
+	pci_read_config_dword(dev, 0x40, &val);
+	if ((val & 0x0000ff00) != 0)
+		pci_write_config_dword(dev, 0x40, val & 0xffff00ff);
+
+	err = ssb_bus_pcibus_register(ssb, dev);
+	if (err)
+		goto err_pci_release_regions;
+
+	pci_set_drvdata(dev, ssb);
+
+out:
+	return err;
+
+err_pci_release_regions:
+	pci_release_regions(dev);
+err_pci_disable:
+	pci_disable_device(dev);
+err_kfree_ssb:
+	kfree(ssb);
+	return err;
+}
+
+static void ssb_pcihost_remove(struct pci_dev *dev)
+{
+	struct ssb_bus *ssb = pci_get_drvdata(dev);
+
+	ssb_bus_unregister(ssb);
+	pci_release_regions(dev);
+	pci_disable_device(dev);
+	kfree(ssb);
+	pci_set_drvdata(dev, NULL);
+}
+
+int ssb_pcihost_register(struct pci_driver *driver)
+{
+	driver->probe = ssb_pcihost_probe;
+	driver->remove = ssb_pcihost_remove;
+#ifdef CONFIG_PM_SLEEP
+	driver->driver.pm = &ssb_pcihost_pm_ops;
+#endif
+
+	return pci_register_driver(driver);
+}
+EXPORT_SYMBOL(ssb_pcihost_register);