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, 99 insertions, 0 deletions

diff --git a/drivers/reset/reset-gpio.c b/drivers/reset/reset-gpio.c
new file mode 100644
index 000000000..bf95296a5
--- /dev/null
+++ b/drivers/reset/reset-gpio.c
@@ -0,0 +1,99 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/auxiliary_bus.h>
+#include <linux/gpio/consumer.h>
+#include <linux/module.h>
+#include <linux/property.h>
+#include <linux/reset-controller.h>
+
+struct reset_gpio_priv {
+	struct reset_controller_dev rc;
+	struct gpio_desc *reset;
+};
+
+static inline struct reset_gpio_priv
+*rc_to_reset_gpio(struct reset_controller_dev *rc)
+{
+	return container_of(rc, struct reset_gpio_priv, rc);
+}
+
+static int reset_gpio_assert(struct reset_controller_dev *rc, unsigned long id)
+{
+	struct reset_gpio_priv *priv = rc_to_reset_gpio(rc);
+
+	return gpiod_set_value_cansleep(priv->reset, 1);
+}
+
+static int reset_gpio_deassert(struct reset_controller_dev *rc,
+			       unsigned long id)
+{
+	struct reset_gpio_priv *priv = rc_to_reset_gpio(rc);
+
+	return gpiod_set_value_cansleep(priv->reset, 0);
+}
+
+static int reset_gpio_status(struct reset_controller_dev *rc, unsigned long id)
+{
+	struct reset_gpio_priv *priv = rc_to_reset_gpio(rc);
+
+	return gpiod_get_value_cansleep(priv->reset);
+}
+
+static const struct reset_control_ops reset_gpio_ops = {
+	.assert = reset_gpio_assert,
+	.deassert = reset_gpio_deassert,
+	.status = reset_gpio_status,
+};
+
+static int reset_gpio_fwnode_xlate(struct reset_controller_dev *rcdev,
+				   const struct fwnode_reference_args *reset_spec)
+{
+	return reset_spec->args[0];
+}
+
+static int reset_gpio_probe(struct auxiliary_device *adev,
+			    const struct auxiliary_device_id *id)
+{
+	struct device *dev = &adev->dev;
+	struct reset_gpio_priv *priv;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
+	if (IS_ERR(priv->reset))
+		return dev_err_probe(dev, PTR_ERR(priv->reset),
+				     "Could not get reset gpios\n");
+
+	priv->rc.ops = &reset_gpio_ops;
+	priv->rc.owner = THIS_MODULE;
+	priv->rc.dev = dev;
+
+	/* Cells to match GPIO specifier, but it's not really used */
+	priv->rc.fwnode_reset_n_cells = 2;
+	priv->rc.fwnode_xlate = reset_gpio_fwnode_xlate;
+	priv->rc.nr_resets = 1;
+
+	return devm_reset_controller_register(dev, &priv->rc);
+}
+
+static const struct auxiliary_device_id reset_gpio_ids[] = {
+	{ .name = "reset.gpio" },
+	{}
+};
+MODULE_DEVICE_TABLE(auxiliary, reset_gpio_ids);
+
+static struct auxiliary_driver reset_gpio_driver = {
+	.probe		= reset_gpio_probe,
+	.id_table	= reset_gpio_ids,
+	.driver	= {
+		.name = "reset-gpio",
+		.suppress_bind_attrs = true,
+	},
+};
+module_auxiliary_driver(reset_gpio_driver);
+
+MODULE_AUTHOR("Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>");
+MODULE_DESCRIPTION("Generic GPIO reset driver");
+MODULE_LICENSE("GPL");