STRUCT IRIS_HFI_BUFFER(9)

🦋 struct iris_hfi_buffer(9) 🦋

okay so bestie, welcome to the Kernel API Manual — this is the struct iris_hfi_buffer(9) page and honestly it's giving "the blueprint of how a buffer talks to firmware." no cap, she's iconic. let's get into it 💅

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✨ NAME ✨

struct iris_hfi_buffer — literally just her name, that's it, that's the whole entry 🎀 (the original page had a lil dash and nothing after it, so we're not making stuff up)

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🌸 SYNOPSIS 🌸

here's the whole struct, copied exactly, do not touch, do not edit, she is perfect:

struct iris_hfi_buffer {
    u32 type;
    u32 index;
    u64 base_address;
    u32 addr_offset;
    u32 buffer_size;
    u32 data_offset;
    u32 data_size;
    u64 timestamp;
    u32 flags;
    u32 reserved[5];
 };

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👑 Members 👑

okay so each of these is a member of the struct, and every single one is lowkey important, so let's do a vibe check one by one 🫶

• type — the buffer type, indicated by "enum hfi_buffer_type". FW needs to return the proper type for any buffer command. fr fr, firmware's gotta get the type right or it's a whole mess 😭
• index — the index of the buffer. that's it, that's the whole thing ✨
• base_address — base address of the buffer. this buffer address is always 4KBytes aligned. always. no exceptions, bestie 💀
• addr_offset — the accessible buffer offset from the base address.
  • decoder bitstream buffer: 256 Bytes aligned.
  • firmware can uniquely identify a buffer based on base_address & addr_offset.
  • HW can read memory only from base_address+addr_offset. like, that's the only place it's allowed to look 🙈
• buffer_size — accessible buffer size in bytes, starting from addr_offset. it's the size of the vibe-check window, iykyk 🌈
• data_offset — data starts from "base_address + addr_offset + data_offset".
  • RAW buffer: data_offset is 0. Restriction: 4KBytes aligned.
  • decoder bitstream buffer: no restriction (can be any value). she's flexible, we respect it 💜
• data_size — data size in bytes. simple, clean, iconic ⭐
• timestamp — timestamp of the buffer in nano seconds (ns). it's the Presentation timestamp (PTS) for encoder & decoder.
  • decoder: it is pass through from bitstream to raw buffer. firmware does not need to return as part of input buffer done.
  • for any internal buffers: there is no timestamp. host sets as 0.

ngl, the "host sets as 0" part is important — for internal buffers it's literally zero, don't come for her 🍓

• flags — buffer flags. it is represented as bit masks.
  • host buffer flags are "enum hfi_buffer_host_flags"
  • firmware buffer flags are "enum hfi_buffer_firmware_flags"

two different flag enums, don't mix them up bestie, that's the trap 🕳️

• reserved — reserved for future use. it's reserved[5], she's saving seats for the future besties 🎟️✨

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🔥 SEE ALSO 🔥

• Kernel file ./drivers/media/platform/qcom/iris/iris_hfi_gen2_packet.h — go read the source, she ate 💅
• struct iris_hfi_header(9)
• struct iris_hfi_packet(9)

like, these are her friends, they come as a set, main character energy all around 👑

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aaaaand that's the page!! 🎀 live from ./drivers/media/platform/qcom/..., dated October 2026 — see you in the future, bestie, mwah 💖🦋✨