From 106b4a2a78b2a2f14885604891957b84bba502db Mon Sep 17 00:00:00 2001 From: Adrian Betschart Date: Fri, 11 Sep 2026 17:13:14 +0200 Subject: drm/amd/display: Try RGB before YCbCr 4:4:4 in stream validation 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 Assisted-by: Claude Code:claude-fable-5-1 Signed-off-by: Adrian Betschart Reviewed-by: Fangzhi Zuo Tested-by: Adolfo Rodrigues Tested-by: Daniel Wheeler Signed-off-by: Alex Deucher (cherry picked from commit 7de432bc753133764dc40d37f9388da56de251e7) --- drivers/usb/misc/usb4604.c | 163 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 163 insertions(+) create mode 100644 drivers/usb/misc/usb4604.c (limited to 'drivers/usb/misc/usb4604.c') diff --git a/drivers/usb/misc/usb4604.c b/drivers/usb/misc/usb4604.c new file mode 100644 index 000000000..2ae965671 --- /dev/null +++ b/drivers/usb/misc/usb4604.c @@ -0,0 +1,163 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Driver for SMSC USB4604 USB HSIC 4-port 2.0 hub controller driver + * Based on usb3503 driver + * + * Copyright (c) 2012-2013 Dongjin Kim (tobetter@gmail.com) + * Copyright (c) 2016 Linaro Ltd. + */ + +#include +#include +#include +#include +#include + +enum usb4604_mode { + USB4604_MODE_UNKNOWN, + USB4604_MODE_HUB, + USB4604_MODE_STANDBY, +}; + +struct usb4604 { + enum usb4604_mode mode; + struct device *dev; + struct gpio_desc *gpio_reset; +}; + +static void usb4604_reset(struct usb4604 *hub, int state) +{ + gpiod_set_value_cansleep(hub->gpio_reset, state); + + /* Wait for i2c logic to come up */ + if (state) + msleep(250); +} + +static int usb4604_connect(struct usb4604 *hub) +{ + struct device *dev = hub->dev; + struct i2c_client *client = to_i2c_client(dev); + int err; + u8 connect_cmd[] = { 0xaa, 0x55, 0x00 }; + + usb4604_reset(hub, 1); + + err = i2c_master_send(client, connect_cmd, ARRAY_SIZE(connect_cmd)); + if (err < 0) { + usb4604_reset(hub, 0); + return err; + } + + hub->mode = USB4604_MODE_HUB; + dev_dbg(dev, "switched to HUB mode\n"); + + return 0; +} + +static int usb4604_switch_mode(struct usb4604 *hub, enum usb4604_mode mode) +{ + struct device *dev = hub->dev; + int err = 0; + + switch (mode) { + case USB4604_MODE_HUB: + err = usb4604_connect(hub); + break; + + case USB4604_MODE_STANDBY: + usb4604_reset(hub, 0); + dev_dbg(dev, "switched to STANDBY mode\n"); + break; + + default: + dev_err(dev, "unknown mode is requested\n"); + err = -EINVAL; + break; + } + + return err; +} + +static int usb4604_probe(struct usb4604 *hub) +{ + struct device *dev = hub->dev; + struct device_node *np = dev->of_node; + struct gpio_desc *gpio; + u32 mode = USB4604_MODE_HUB; + + gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW); + if (IS_ERR(gpio)) + return PTR_ERR(gpio); + hub->gpio_reset = gpio; + + if (of_property_read_u32(np, "initial-mode", &hub->mode)) + hub->mode = mode; + + return usb4604_switch_mode(hub, hub->mode); +} + +static int usb4604_i2c_probe(struct i2c_client *i2c) +{ + struct usb4604 *hub; + + hub = devm_kzalloc(&i2c->dev, sizeof(*hub), GFP_KERNEL); + if (!hub) + return -ENOMEM; + + i2c_set_clientdata(i2c, hub); + hub->dev = &i2c->dev; + + return usb4604_probe(hub); +} + +static int __maybe_unused usb4604_i2c_suspend(struct device *dev) +{ + struct i2c_client *client = to_i2c_client(dev); + struct usb4604 *hub = i2c_get_clientdata(client); + + usb4604_switch_mode(hub, USB4604_MODE_STANDBY); + + return 0; +} + +static int __maybe_unused usb4604_i2c_resume(struct device *dev) +{ + struct i2c_client *client = to_i2c_client(dev); + struct usb4604 *hub = i2c_get_clientdata(client); + + usb4604_switch_mode(hub, hub->mode); + + return 0; +} + +static SIMPLE_DEV_PM_OPS(usb4604_i2c_pm_ops, usb4604_i2c_suspend, + usb4604_i2c_resume); + +static const struct i2c_device_id usb4604_id[] = { + { .name = "usb4604" }, + { } +}; +MODULE_DEVICE_TABLE(i2c, usb4604_id); + +#ifdef CONFIG_OF +static const struct of_device_id usb4604_of_match[] = { + { .compatible = "smsc,usb4604" }, + {} +}; +MODULE_DEVICE_TABLE(of, usb4604_of_match); +#endif + +static struct i2c_driver usb4604_i2c_driver = { + .driver = { + .name = "usb4604", + .pm = pm_ptr(&usb4604_i2c_pm_ops), + .of_match_table = of_match_ptr(usb4604_of_match), + }, + .probe = usb4604_i2c_probe, + .id_table = usb4604_id, +}; +module_i2c_driver(usb4604_i2c_driver); + +MODULE_DESCRIPTION("USB4604 USB HUB driver"); +MODULE_LICENSE("GPL v2"); -- cgit v1.3.1