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) --- lib/test_sysctl.c | 335 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 335 insertions(+) create mode 100644 lib/test_sysctl.c (limited to 'lib/test_sysctl.c') diff --git a/lib/test_sysctl.c b/lib/test_sysctl.c new file mode 100644 index 000000000..909cfcf76 --- /dev/null +++ b/lib/test_sysctl.c @@ -0,0 +1,335 @@ +// SPDX-License-Identifier: GPL-2.0-or-later OR copyleft-next-0.3.1 +/* + * proc sysctl test driver + * + * Copyright (C) 2017 Luis R. Rodriguez + */ + +/* + * This module provides an interface to the proc sysctl interfaces. This + * driver requires CONFIG_SYSCTL. It will not normally be loaded by the + * system unless explicitly requested by name. You can also build this driver + * into your kernel. + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +static int i_zero; +static int i_one_hundred = 100; +static int match_int_ok = 1; + +enum { + TEST_H_SETUP_NODE, + TEST_H_MNT, + TEST_H_MNTERROR, + TEST_H_EMPTY_ADD, + TEST_H_EMPTY, + TEST_H_U8, + TEST_H_SIZE /* Always at the end */ +}; + +static struct ctl_table_header *ctl_headers[TEST_H_SIZE] = {}; +struct test_sysctl_data { + int int_0001; + int int_0002; + int int_0003[4]; + + int boot_int; + + unsigned int uint_0001; + + char string_0001[65]; + +#define SYSCTL_TEST_BITMAP_SIZE 65536 + unsigned long *bitmap_0001; +}; + +static struct test_sysctl_data test_data = { + .int_0001 = 60, + .int_0002 = 1, + + .int_0003[0] = 0, + .int_0003[1] = 1, + .int_0003[2] = 2, + .int_0003[3] = 3, + + .boot_int = 0, + + .uint_0001 = 314, + + .string_0001 = "(none)", +}; + +/* These are all under /proc/sys/debug/test_sysctl/ */ +static const struct ctl_table test_table[] = { + { + .procname = "int_0001", + .data = &test_data.int_0001, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec_minmax, + .extra1 = &i_zero, + .extra2 = &i_one_hundred, + }, + { + .procname = "int_0002", + .data = &test_data.int_0002, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec, + }, + { + .procname = "int_0003", + .data = &test_data.int_0003, + .maxlen = sizeof(test_data.int_0003), + .mode = 0644, + .proc_handler = proc_dointvec, + }, + { + .procname = "match_int", + .data = &match_int_ok, + .maxlen = sizeof(match_int_ok), + .mode = 0444, + .proc_handler = proc_dointvec, + }, + { + .procname = "boot_int", + .data = &test_data.boot_int, + .maxlen = sizeof(test_data.boot_int), + .mode = 0644, + .proc_handler = proc_dointvec, + .extra1 = SYSCTL_ZERO, + .extra2 = SYSCTL_ONE, + }, + { + .procname = "uint_0001", + .data = &test_data.uint_0001, + .maxlen = sizeof(unsigned int), + .mode = 0644, + .proc_handler = proc_douintvec, + }, + { + .procname = "string_0001", + .data = &test_data.string_0001, + .maxlen = sizeof(test_data.string_0001), + .mode = 0644, + .proc_handler = proc_dostring, + }, + { + .procname = "bitmap_0001", + .data = &test_data.bitmap_0001, + .maxlen = SYSCTL_TEST_BITMAP_SIZE, + .mode = 0644, + .proc_handler = proc_do_large_bitmap, + }, +}; + +static void test_sysctl_calc_match_int_ok(void) +{ + int i; + + struct { + int defined; + int wanted; + } match_int[] = { + {.defined = *(int *)SYSCTL_ZERO, .wanted = 0}, + {.defined = *(int *)SYSCTL_ONE, .wanted = 1}, + {.defined = *(int *)SYSCTL_TWO, .wanted = 2}, + {.defined = *(int *)SYSCTL_THREE, .wanted = 3}, + {.defined = *(int *)SYSCTL_FOUR, .wanted = 4}, + {.defined = *(int *)SYSCTL_ONE_HUNDRED, .wanted = 100}, + {.defined = *(int *)SYSCTL_TWO_HUNDRED, .wanted = 200}, + {.defined = *(int *)SYSCTL_ONE_THOUSAND, .wanted = 1000}, + {.defined = *(int *)SYSCTL_THREE_THOUSAND, .wanted = 3000}, + {.defined = *(int *)SYSCTL_INT_MAX, .wanted = INT_MAX}, + {.defined = *(int *)SYSCTL_MAXOLDUID, .wanted = 65535}, + {.defined = *(int *)SYSCTL_NEG_ONE, .wanted = -1}, + }; + + for (i = 0; i < ARRAY_SIZE(match_int); i++) + if (match_int[i].defined != match_int[i].wanted) + match_int_ok = 0; +} + +static int test_sysctl_setup_node_tests(void) +{ + test_sysctl_calc_match_int_ok(); + test_data.bitmap_0001 = kzalloc(SYSCTL_TEST_BITMAP_SIZE/8, GFP_KERNEL); + if (!test_data.bitmap_0001) + return -ENOMEM; + ctl_headers[TEST_H_SETUP_NODE] = register_sysctl("debug/test_sysctl", test_table); + if (!ctl_headers[TEST_H_SETUP_NODE]) { + kfree(test_data.bitmap_0001); + return -ENOMEM; + } + + return 0; +} + +/* Used to test that unregister actually removes the directory */ +static const struct ctl_table test_table_unregister[] = { + { + .procname = "unregister_error", + .data = &test_data.int_0001, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec_minmax, + }, +}; + +static int test_sysctl_run_unregister_nested(void) +{ + struct ctl_table_header *unregister; + + unregister = register_sysctl("debug/test_sysctl/unregister_error", + test_table_unregister); + if (!unregister) + return -ENOMEM; + + unregister_sysctl_table(unregister); + return 0; +} + +static int test_sysctl_run_register_mount_point(void) +{ + ctl_headers[TEST_H_MNT] + = register_sysctl_mount_point("debug/test_sysctl/mnt"); + if (!ctl_headers[TEST_H_MNT]) + return -ENOMEM; + + ctl_headers[TEST_H_MNTERROR] + = register_sysctl("debug/test_sysctl/mnt/mnt_error", + test_table_unregister); + /* + * Don't check the result.: + * If it fails (expected behavior), return 0. + * If successful (missbehavior of register mount point), we want to see + * mnt_error when we run the sysctl test script + */ + + return 0; +} + +static const struct ctl_table test_table_empty[] = { }; + +static int test_sysctl_run_register_empty(void) +{ + /* Tets that an empty dir can be created */ + ctl_headers[TEST_H_EMPTY_ADD] + = register_sysctl("debug/test_sysctl/empty_add", test_table_empty); + if (!ctl_headers[TEST_H_EMPTY_ADD]) + return -ENOMEM; + + /* Test that register on top of an empty dir works */ + ctl_headers[TEST_H_EMPTY] + = register_sysctl("debug/test_sysctl/empty_add/empty", test_table_empty); + if (!ctl_headers[TEST_H_EMPTY]) + return -ENOMEM; + + return 0; +} + +static const struct ctl_table table_u8_over[] = { + { + .procname = "u8_over", + .data = &test_data.uint_0001, + .maxlen = sizeof(u8), + .mode = 0644, + .proc_handler = proc_dou8vec_minmax, + .extra1 = SYSCTL_FOUR, + .extra2 = SYSCTL_ONE_THOUSAND, + }, +}; + +static const struct ctl_table table_u8_under[] = { + { + .procname = "u8_under", + .data = &test_data.uint_0001, + .maxlen = sizeof(u8), + .mode = 0644, + .proc_handler = proc_dou8vec_minmax, + .extra1 = SYSCTL_NEG_ONE, + .extra2 = SYSCTL_ONE_HUNDRED, + }, +}; + +static const struct ctl_table table_u8_valid[] = { + { + .procname = "u8_valid", + .data = &test_data.uint_0001, + .maxlen = sizeof(u8), + .mode = 0644, + .proc_handler = proc_dou8vec_minmax, + .extra1 = SYSCTL_ZERO, + .extra2 = SYSCTL_TWO_HUNDRED, + }, +}; + +static int test_sysctl_register_u8_extra(void) +{ + /* should fail because it's over */ + ctl_headers[TEST_H_U8] + = register_sysctl("debug/test_sysctl", table_u8_over); + if (ctl_headers[TEST_H_U8]) + return -ENOMEM; + + /* should fail because it's under */ + ctl_headers[TEST_H_U8] + = register_sysctl("debug/test_sysctl", table_u8_under); + if (ctl_headers[TEST_H_U8]) + return -ENOMEM; + + /* should not fail because it's valid */ + ctl_headers[TEST_H_U8] + = register_sysctl("debug/test_sysctl", table_u8_valid); + if (!ctl_headers[TEST_H_U8]) + return -ENOMEM; + + return 0; +} + +static int __init test_sysctl_init(void) +{ + int err = 0; + + int (*func_array[])(void) = { + test_sysctl_setup_node_tests, + test_sysctl_run_unregister_nested, + test_sysctl_run_register_mount_point, + test_sysctl_run_register_empty, + test_sysctl_register_u8_extra + }; + + for (int i = 0; !err && i < ARRAY_SIZE(func_array); i++) + err = func_array[i](); + + return err; +} +module_init(test_sysctl_init); + +static void __exit test_sysctl_exit(void) +{ + kfree(test_data.bitmap_0001); + for (int i = 0; i < TEST_H_SIZE; i++) { + if (ctl_headers[i]) + unregister_sysctl_table(ctl_headers[i]); + } +} + +module_exit(test_sysctl_exit); + +MODULE_AUTHOR("Luis R. Rodriguez "); +MODULE_DESCRIPTION("proc sysctl test driver"); +MODULE_LICENSE("GPL"); -- cgit v1.3.1