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/rpmsg/rpmsg_ns.c | 124 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 124 insertions(+) create mode 100644 drivers/rpmsg/rpmsg_ns.c (limited to 'drivers/rpmsg/rpmsg_ns.c') diff --git a/drivers/rpmsg/rpmsg_ns.c b/drivers/rpmsg/rpmsg_ns.c new file mode 100644 index 000000000..bde8c8d43 --- /dev/null +++ b/drivers/rpmsg/rpmsg_ns.c @@ -0,0 +1,124 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) STMicroelectronics 2020 - All Rights Reserved + */ +#include +#include +#include +#include +#include +#include + +#include "rpmsg_internal.h" + +/** + * rpmsg_ns_register_device() - register name service device based on rpdev + * @rpdev: prepared rpdev to be used for creating endpoints + * + * This function wraps rpmsg_register_device() preparing the rpdev for use as + * basis for the rpmsg name service device. + */ +int rpmsg_ns_register_device(struct rpmsg_device *rpdev) +{ + rpdev->src = RPMSG_NS_ADDR; + rpdev->dst = RPMSG_NS_ADDR; + + return rpmsg_register_device_override(rpdev, "rpmsg_ns"); +} +EXPORT_SYMBOL(rpmsg_ns_register_device); + +/* invoked when a name service announcement arrives */ +static int rpmsg_ns_cb(struct rpmsg_device *rpdev, void *data, int len, + void *priv, u32 src) +{ + struct rpmsg_ns_msg *msg = data; + struct rpmsg_device *newch; + struct rpmsg_channel_info chinfo; + struct device *dev = rpdev->dev.parent; + int ret; + +#if defined(CONFIG_DYNAMIC_DEBUG) + dynamic_hex_dump("NS announcement: ", DUMP_PREFIX_NONE, 16, 1, + data, len, true); +#endif + + if (len != sizeof(*msg)) { + dev_err(dev, "malformed ns msg (%d)\n", len); + return -EINVAL; + } + + /* don't trust the remote processor for null terminating the name */ + msg->name[RPMSG_NAME_SIZE - 1] = '\0'; + + strscpy_pad(chinfo.name, msg->name, sizeof(chinfo.name)); + chinfo.src = RPMSG_ADDR_ANY; + chinfo.dst = rpmsg32_to_cpu(rpdev, msg->addr); + + dev_info(dev, "%sing channel %s addr 0x%x\n", + rpmsg32_to_cpu(rpdev, msg->flags) & RPMSG_NS_DESTROY ? + "destroy" : "creat", msg->name, chinfo.dst); + + if (rpmsg32_to_cpu(rpdev, msg->flags) & RPMSG_NS_DESTROY) { + ret = rpmsg_release_channel(rpdev, &chinfo); + if (ret) + dev_err(dev, "rpmsg_destroy_channel failed: %d\n", ret); + } else { + newch = rpmsg_create_channel(rpdev, &chinfo); + if (!newch) + dev_err(dev, "rpmsg_create_channel failed\n"); + } + + return 0; +} + +static int rpmsg_ns_probe(struct rpmsg_device *rpdev) +{ + struct rpmsg_endpoint *ns_ept; + struct rpmsg_channel_info ns_chinfo = { + .src = RPMSG_NS_ADDR, + .dst = RPMSG_NS_ADDR, + .name = "name_service", + }; + + /* + * Create the NS announcement service endpoint associated to the RPMsg + * device. The endpoint will be automatically destroyed when the RPMsg + * device will be deleted. + */ + ns_ept = rpmsg_create_ept(rpdev, rpmsg_ns_cb, NULL, ns_chinfo); + if (!ns_ept) { + dev_err(&rpdev->dev, "failed to create the ns ept\n"); + return -ENOMEM; + } + rpdev->ept = ns_ept; + + return 0; +} + +static struct rpmsg_driver rpmsg_ns_driver = { + .drv.name = KBUILD_MODNAME, + .probe = rpmsg_ns_probe, +}; + +static int rpmsg_ns_init(void) +{ + int ret; + + ret = register_rpmsg_driver(&rpmsg_ns_driver); + if (ret < 0) + pr_err("%s: Failed to register rpmsg driver\n", __func__); + + return ret; +} +postcore_initcall(rpmsg_ns_init); + +static void rpmsg_ns_exit(void) +{ + unregister_rpmsg_driver(&rpmsg_ns_driver); +} +module_exit(rpmsg_ns_exit); + +MODULE_DESCRIPTION("Name service announcement rpmsg driver"); +MODULE_AUTHOR("Arnaud Pouliquen "); +MODULE_ALIAS("rpmsg:" KBUILD_MODNAME); +MODULE_LICENSE("GPL v2"); -- cgit v1.3.1