The table describes how each bit in the u64 value is used. Explicitly state which values a field can take if we have defines for them. Also add a note when a field isn't always populated. Forcing people to update the table when changing the bit layout should make it more obvious when there's a mistake, I hope. If we get to the point where the bit layout gets more complicated, it might be worth it to split the table into multiple tables (e.g. one for GFX8, one for GFX9+, and so on). Signed-off-by: Simon Ser <contact@xxxxxxxxxxx> Cc: Bas Nieuwenhuizen <bas@xxxxxxxxxxxxxxxxxxx> Cc: Alex Deucher <alexdeucher@xxxxxxxxx> Cc: Daniel Vetter <daniel@xxxxxxxx> --- This already contains the fix in [1]. [1]: https://lists.freedesktop.org/archives/amd-gfx/2020-November/056073.html include/uapi/drm/drm_fourcc.h | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) diff --git a/include/uapi/drm/drm_fourcc.h b/include/uapi/drm/drm_fourcc.h index ca48ed0e6bc1..253386b7bc6a 100644 --- a/include/uapi/drm/drm_fourcc.h +++ b/include/uapi/drm/drm_fourcc.h @@ -1114,6 +1114,25 @@ drm_fourcc_canonicalize_nvidia_format_mod(__u64 modifier) * * For multi-plane formats the above surfaces get merged into one plane for * each format plane, based on the required alignment only. + * + * Bits Parameter Notes + * ----- ------------------------ --------------------------------------------- + * + * 7:0 TILE_VERSION Values are AMD_FMT_MOD_TILE_VER_* + * 12:8 TILE Values are AMD_FMT_MOD_TILE_<version>_* + * 13 DCC + * 14 DCC_RETILE + * 15 DCC_PIPE_ALIGN + * 16 DCC_INDEPENDENT_64B + * 17 DCC_INDEPENDENT_128B + * 19:18 DCC_MAX_COMPRESSED_BLOCK Values are AMD_FMT_MOD_DCC_BLOCK_* + * 20 DCC_CONSTANT_ENCODE + * 23:21 PIPE_XOR_BITS Only for some chips + * 26:24 BANK_XOR_BITS Only for some chips + * 29:27 PACKERS Only for some chips + * 32:30 RB Only for some chips + * 35:33 PIPE Only for some chips + * 55:36 - Reserved for future use, must be zero */ #define AMD_FMT_MOD fourcc_mod_code(AMD, 0) -- 2.29.2 _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
