STRUCT XILINX_DPDMA_CHAN(9)

📦 version 7.3.1, in nixpkgs unstable

💅 struct xilinx_dpdma_chan(9) — like, the DPDMA channel struct bestie

okay so real talk, this is from the Kernel API Manual and it's literally the definition of struct xilinx_dpdma_chan, aka the DPDMA channel. one struct, so many little fields, all of them iconic in their own way ✨

🎀 NAME 🎀

struct xilinx_dpdma_chan — DPDMA channel. that's the whole vibe. it's a channel. it does DPDMA. slay.

🌸 SYNOPSIS 🌸

struct xilinx_dpdma_chan {
    struct virt_dma_chan vchan;
    void __iomem *reg;
    unsigned int id;
    wait_queue_head_t wait_to_stop;
    bool running;
    bool first_frame;
    bool video_group;
    spinlock_t lock;
    struct dma_pool *desc_pool;
    struct tasklet_struct err_task;
    struct {
      struct xilinx_dpdma_tx_desc *pending;
      struct xilinx_dpdma_tx_desc *active;
    } desc;
    struct xilinx_dpdma_device *xdev;
 };

no cap, that's the whole thing verbatim, every field, every brace. do not touch 🫶

🦋 Members 🦋

okay bestie, field-by-field tour, let's go:

  • vchan — the virtual DMA channel. it's giving "the actual channel energy" 💫
  • reg — register base address. where the hardware lives, fr fr.
  • id — the channel ID. every channel needs to know its own name 🎀
  • wait_to_stop — a queue you wait on for outstanding transactions before stopping. like, hold up, let the pending stuff finish first 😭
  • running — true if the channel is running. simple as that, king 👑
  • first_frame — flag for the first frame of the stream. the debut frame, main character energy ⭐
  • video_group — flag if multi-channel operation is needed for the video channels. squad goals 🌈
  • lock — lock to access struct xilinx_dpdma_chan. ⚠️ and this is the important bit: it must be taken before vchan.lock, if both are to be held. lock order is not a suggestion, bestie, it's the law 💀
  • desc_pool — the descriptor allocation pool. it's where the descriptors hang out 🍓
  • err_task — error IRQ bottom half handler. the cleanup crew for when things go wrong 🙈
  • desc — references to descriptors being processed. the whole processing pipeline lives here ✨
    • desc.pending — descriptor scheduled to the hardware, pending execution. waiting its turn, lowkey patient 🧚
    • desc.active — descriptor being executed by the hardware right now. currently booked and busy 🔥
  • xdev — the DPDMA device. the parent, the icon, the whole reason this channel exists 💜

💖 SEE ALSO 💖

go read these next, iykyk:

and that's the whole page bestie, mwah 💋 this little masterpiece lives at ./drivers/dma/xilinx and it's dated October 2026 — so like, future vibes only. periodt. 🦋💅

📦 where this page comes from