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) --- samples/watch_queue/.gitignore | 2 + samples/watch_queue/Makefile | 4 + samples/watch_queue/watch_test.c | 192 +++++++++++++++++++++++++++++++++++++++ 3 files changed, 198 insertions(+) create mode 100644 samples/watch_queue/.gitignore create mode 100644 samples/watch_queue/Makefile create mode 100644 samples/watch_queue/watch_test.c (limited to 'samples/watch_queue') diff --git a/samples/watch_queue/.gitignore b/samples/watch_queue/.gitignore new file mode 100644 index 000000000..823b351d3 --- /dev/null +++ b/samples/watch_queue/.gitignore @@ -0,0 +1,2 @@ +# SPDX-License-Identifier: GPL-2.0-only +/watch_test diff --git a/samples/watch_queue/Makefile b/samples/watch_queue/Makefile new file mode 100644 index 000000000..c0db3a6bc --- /dev/null +++ b/samples/watch_queue/Makefile @@ -0,0 +1,4 @@ +# SPDX-License-Identifier: GPL-2.0-only +userprogs-always-y += watch_test + +userccflags += -I usr/include diff --git a/samples/watch_queue/watch_test.c b/samples/watch_queue/watch_test.c new file mode 100644 index 000000000..24cf7d7a1 --- /dev/null +++ b/samples/watch_queue/watch_test.c @@ -0,0 +1,192 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Use watch_queue API to watch for notifications. + * + * Copyright (C) 2020 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + */ + +#define _GNU_SOURCE +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +// Work around glibc header silliness +#undef AT_RENAME_NOREPLACE +#undef AT_RENAME_EXCHANGE +#undef AT_RENAME_WHITEOUT + +#include +#include +#include + +#ifndef KEYCTL_WATCH_KEY +#define KEYCTL_WATCH_KEY -1 +#endif +#ifndef __NR_keyctl +#define __NR_keyctl -1 +#endif + +#define BUF_SIZE 256 + +static long keyctl_watch_key(int key, int watch_fd, int watch_id) +{ + return syscall(__NR_keyctl, KEYCTL_WATCH_KEY, key, watch_fd, watch_id); +} + +static const char *key_subtypes[256] = { + [NOTIFY_KEY_INSTANTIATED] = "instantiated", + [NOTIFY_KEY_UPDATED] = "updated", + [NOTIFY_KEY_LINKED] = "linked", + [NOTIFY_KEY_UNLINKED] = "unlinked", + [NOTIFY_KEY_CLEARED] = "cleared", + [NOTIFY_KEY_REVOKED] = "revoked", + [NOTIFY_KEY_INVALIDATED] = "invalidated", + [NOTIFY_KEY_SETATTR] = "setattr", +}; + +static void saw_key_change(struct watch_notification *n, size_t len) +{ + struct key_notification *k = (struct key_notification *)n; + + if (len != sizeof(struct key_notification)) { + fprintf(stderr, "Incorrect key message length\n"); + return; + } + + printf("KEY %08x change=%u[%s] aux=%u\n", + k->key_id, n->subtype, key_subtypes[n->subtype], k->aux); +} + +/* + * Consume and display events. + */ +static void consumer(int fd) +{ + unsigned char buffer[433], *p, *end; + union { + struct watch_notification n; + unsigned char buf1[128]; + } n; + ssize_t buf_len; + + for (;;) { + buf_len = read(fd, buffer, sizeof(buffer)); + if (buf_len == -1) { + perror("read"); + exit(1); + } + + if (buf_len == 0) { + printf("-- END --\n"); + return; + } + + if (buf_len > sizeof(buffer)) { + fprintf(stderr, "Read buffer overrun: %zd\n", buf_len); + return; + } + + printf("read() = %zd\n", buf_len); + + p = buffer; + end = buffer + buf_len; + while (p < end) { + size_t largest, len; + + largest = end - p; + if (largest > 128) + largest = 128; + if (largest < sizeof(struct watch_notification)) { + fprintf(stderr, "Short message header: %zu\n", largest); + return; + } + memcpy(&n, p, largest); + + printf("NOTIFY[%03zx]: ty=%06x sy=%02x i=%08x\n", + p - buffer, n.n.type, n.n.subtype, n.n.info); + + len = n.n.info & WATCH_INFO_LENGTH; + if (len < sizeof(n.n) || len > largest) { + fprintf(stderr, "Bad message length: %zu/%zu\n", len, largest); + exit(1); + } + + switch (n.n.type) { + case WATCH_TYPE_META: + switch (n.n.subtype) { + case WATCH_META_REMOVAL_NOTIFICATION: + printf("REMOVAL of watchpoint %08x\n", + (n.n.info & WATCH_INFO_ID) >> + WATCH_INFO_ID__SHIFT); + break; + case WATCH_META_LOSS_NOTIFICATION: + printf("-- LOSS --\n"); + break; + default: + printf("other meta record\n"); + break; + } + break; + case WATCH_TYPE_KEY_NOTIFY: + saw_key_change(&n.n, len); + break; + default: + printf("other type\n"); + break; + } + + p += len; + } + } +} + +static struct watch_notification_filter filter = { + .nr_filters = 1, + .filters = { + [0] = { + .type = WATCH_TYPE_KEY_NOTIFY, + .subtype_filter[0] = UINT_MAX, + }, + }, +}; + +int main(int argc, char **argv) +{ + int pipefd[2], fd; + + if (pipe2(pipefd, O_NOTIFICATION_PIPE) == -1) { + perror("pipe2"); + exit(1); + } + fd = pipefd[0]; + + if (ioctl(fd, IOC_WATCH_QUEUE_SET_SIZE, BUF_SIZE) == -1) { + perror("watch_queue(size)"); + exit(1); + } + + if (ioctl(fd, IOC_WATCH_QUEUE_SET_FILTER, &filter) == -1) { + perror("watch_queue(filter)"); + exit(1); + } + + if (keyctl_watch_key(KEY_SPEC_SESSION_KEYRING, fd, 0x01) == -1) { + perror("keyctl"); + exit(1); + } + + if (keyctl_watch_key(KEY_SPEC_USER_KEYRING, fd, 0x02) == -1) { + perror("keyctl"); + exit(1); + } + + consumer(fd); + exit(0); +} -- cgit v1.3.1