STRUCT SND_DMAENGINE_DAI_DMA_DATA(9)

💖 struct snd_dmaengine_dai_dma_data — NAME 💖

okay bestie, so this is struct snd_dmaengine_dai_dma_data — the DAI DMA configuration data. that's it, that's the whole vibe ✨ (and yes, we're in the Kernel API Manual, section 9, if you were wondering 🎀)

✨ SYNOPSIS ✨

here's the whole struct, literally copy-paste it exactly, no cap:

struct snd_dmaengine_dai_dma_data {
    dma_addr_t addr;
    enum dma_slave_buswidth addr_width;
    u32 maxburst;
    void *filter_data;
    const char *chan_name;
    unsigned int fifo_size;
    unsigned int flags;
    void *peripheral_config;
    size_t peripheral_size;
    u32 port_window_size;
 };

look at her. ten whole members. main character energy fr fr 👑

🌸 Members 🌸

okay so now the part where we meet everybody one by one, like a little group chat roll call 🫶

• addr — the address of the DAI data source register or the destination register. where the data actually lives, basically 💅
• addr_width — the width of that source/destination register. how wide the doorway is 🌈
• maxburst — the maximum number of words that can be sent to or received from the DAI in one single burst. important note though, and I'm quoting the vibe exactly: words, as in units of the src_addr_width member, not bytes 😭 so do not come in here counting bytes, bestie, that's not the assignment.
• filter_data — custom DMA channel filter data. this usually gets used when you're requesting the DMA channel. iykyk 🦋
• chan_name — a custom channel name to use when requesting the DMA channel. name your channel, give it a little identity ✨
• fifo_size — the FIFO size of the DAI controller, measured in bytes 🍓
• flags — PCM_DAI flags. and for now it's only SND_DMAENGINE_PCM_DAI_FLAG_PACK — that's the whole roster, that's the only one 💀
• peripheral_config — the peripheral configuration for programming the peripheral for a dmaengine transfer. the lil instruction manual for the peripheral 🎀
• peripheral_size — the size of that peripheral configuration buffer. how much room the instruction manual takes up 📏
• port_window_size — the length of the register area, in words, that the data needs to be accessed on the device side. and listen, this one has lore: it's only used for devices which are using an area instead of a single register to send/receive the data. typically the DMA loops in that area in order to transfer the data 🔁 so like, a whole zone instead of one little spot, and the DMA just laps around it. iconic behaviour honestly 👑

🔥 SEE ALSO 🔥

go look at these next, bestie, they're the friends of this page:

• Kernel file ./include/sound/dmaengine_pcm.h
• snd_pcm_substream_to_dma_direction(9)
• struct snd_dmaengine_pcm_config(9)

okay that's the whole page!! 💜 huge shoutout to ./include/sound for hosting this, and to the October 2026 era for stamping the date on it — and yes, the footer repeats struct snd_...dai_dma_data(9) at us one more time because she loves a dramatic exit 💅 mwah, go configure some DMA, you got this 🧚💖