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) --- scripts/elf-parse.c | 198 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 198 insertions(+) create mode 100644 scripts/elf-parse.c (limited to 'scripts/elf-parse.c') diff --git a/scripts/elf-parse.c b/scripts/elf-parse.c new file mode 100644 index 000000000..99869ff91 --- /dev/null +++ b/scripts/elf-parse.c @@ -0,0 +1,198 @@ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "elf-parse.h" + +struct elf_funcs elf_parser; + +/* + * Get the whole file as a programming convenience in order to avoid + * malloc+lseek+read+free of many pieces. If successful, then mmap + * avoids copying unused pieces; else just read the whole file. + * Open for both read and write. + */ +static void *map_file(char const *fname, size_t *size) +{ + int fd; + struct stat sb; + void *addr = NULL; + + fd = open(fname, O_RDWR); + if (fd < 0) { + perror(fname); + return NULL; + } + if (fstat(fd, &sb) < 0) { + perror(fname); + goto out; + } + if (!S_ISREG(sb.st_mode)) { + fprintf(stderr, "not a regular file: %s\n", fname); + goto out; + } + + addr = mmap(0, sb.st_size, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0); + if (addr == MAP_FAILED) { + fprintf(stderr, "Could not mmap file: %s\n", fname); + goto out; + } + + *size = sb.st_size; + +out: + close(fd); + return addr; +} + +static int elf_parse(const char *fname, void *addr, uint32_t types) +{ + Elf_Ehdr *ehdr = addr; + uint16_t type; + + switch (ehdr->e32.e_ident[EI_DATA]) { + case ELFDATA2LSB: + elf_parser.r = rle; + elf_parser.r2 = r2le; + elf_parser.r8 = r8le; + elf_parser.w = wle; + elf_parser.w8 = w8le; + break; + case ELFDATA2MSB: + elf_parser.r = rbe; + elf_parser.r2 = r2be; + elf_parser.r8 = r8be; + elf_parser.w = wbe; + elf_parser.w8 = w8be; + break; + default: + fprintf(stderr, "unrecognized ELF data encoding %d: %s\n", + ehdr->e32.e_ident[EI_DATA], fname); + return -1; + } + + if (memcmp(ELFMAG, ehdr->e32.e_ident, SELFMAG) != 0 || + ehdr->e32.e_ident[EI_VERSION] != EV_CURRENT) { + fprintf(stderr, "unrecognized ELF file %s\n", fname); + return -1; + } + + type = elf_parser.r2(&ehdr->e32.e_type); + if (!((1 << type) & types)) { + fprintf(stderr, "Invalid ELF type file %s\n", fname); + return -1; + } + + switch (ehdr->e32.e_ident[EI_CLASS]) { + case ELFCLASS32: { + elf_parser.ehdr_shoff = ehdr32_shoff; + elf_parser.ehdr_shentsize = ehdr32_shentsize; + elf_parser.ehdr_shstrndx = ehdr32_shstrndx; + elf_parser.ehdr_shnum = ehdr32_shnum; + elf_parser.shdr_addr = shdr32_addr; + elf_parser.shdr_offset = shdr32_offset; + elf_parser.shdr_link = shdr32_link; + elf_parser.shdr_size = shdr32_size; + elf_parser.shdr_name = shdr32_name; + elf_parser.shdr_type = shdr32_type; + elf_parser.shdr_entsize = shdr32_entsize; + elf_parser.sym_type = sym32_type; + elf_parser.sym_name = sym32_name; + elf_parser.sym_value = sym32_value; + elf_parser.sym_shndx = sym32_shndx; + elf_parser.rela_offset = rela32_offset; + elf_parser.rela_info = rela32_info; + elf_parser.rela_addend = rela32_addend; + elf_parser.rela_write_addend = rela32_write_addend; + + if (elf_parser.r2(&ehdr->e32.e_ehsize) != sizeof(Elf32_Ehdr) || + elf_parser.r2(&ehdr->e32.e_shentsize) != sizeof(Elf32_Shdr)) { + fprintf(stderr, + "unrecognized ET_EXEC/ET_DYN file: %s\n", fname); + return -1; + } + + } + break; + case ELFCLASS64: { + elf_parser.ehdr_shoff = ehdr64_shoff; + elf_parser.ehdr_shentsize = ehdr64_shentsize; + elf_parser.ehdr_shstrndx = ehdr64_shstrndx; + elf_parser.ehdr_shnum = ehdr64_shnum; + elf_parser.shdr_addr = shdr64_addr; + elf_parser.shdr_offset = shdr64_offset; + elf_parser.shdr_link = shdr64_link; + elf_parser.shdr_size = shdr64_size; + elf_parser.shdr_name = shdr64_name; + elf_parser.shdr_type = shdr64_type; + elf_parser.shdr_entsize = shdr64_entsize; + elf_parser.sym_type = sym64_type; + elf_parser.sym_name = sym64_name; + elf_parser.sym_value = sym64_value; + elf_parser.sym_shndx = sym64_shndx; + elf_parser.rela_offset = rela64_offset; + elf_parser.rela_info = rela64_info; + elf_parser.rela_addend = rela64_addend; + elf_parser.rela_write_addend = rela64_write_addend; + + if (elf_parser.r2(&ehdr->e64.e_ehsize) != sizeof(Elf64_Ehdr) || + elf_parser.r2(&ehdr->e64.e_shentsize) != sizeof(Elf64_Shdr)) { + fprintf(stderr, + "unrecognized ET_EXEC/ET_DYN file: %s\n", + fname); + return -1; + } + + } + break; + default: + fprintf(stderr, "unrecognized ELF class %d %s\n", + ehdr->e32.e_ident[EI_CLASS], fname); + return -1; + } + return 0; +} + +int elf_map_machine(void *addr) +{ + Elf_Ehdr *ehdr = addr; + + return elf_parser.r2(&ehdr->e32.e_machine); +} + +int elf_map_long_size(void *addr) +{ + Elf_Ehdr *ehdr = addr; + + return ehdr->e32.e_ident[EI_CLASS] == ELFCLASS32 ? 4 : 8; +} + +void *elf_map(char const *fname, size_t *size, uint32_t types) +{ + void *addr; + int ret; + + addr = map_file(fname, size); + if (!addr) + return NULL; + + ret = elf_parse(fname, addr, types); + if (ret < 0) { + elf_unmap(addr, *size); + return NULL; + } + + return addr; +} + +void elf_unmap(void *addr, size_t size) +{ + munmap(addr, size); +} -- cgit v1.3.1