STRUCT DMA_TX_STATE(9)

🌸 NAME 🌸

Okay bestie, welcome to struct dma_tx_state(9) from the Kernel API Manual ✨ This is the struct that gets filled in to report the status of a transfer. That’s the whole vibe — it’s giving “status report but make it C” 🦋

✨ SYNOPSIS ✨

Here’s the struct in all its main-character glory — copy it exactly, no edits, fr fr:

       struct dma_tx_state {
           dma_cookie_t last;
           dma_cookie_t used;
           u32 residue;
           u32 in_flight_bytes;
        };

🫶 Members 🫶

Member-by-member vibe check, and yes every single one matters 💅

• last — last completed DMA cookie 🍓
• used — last issued DMA cookie (i.e. the one in progress) ✨
• residue — the remaining number of bytes left to transmit on the selected transfer for states DMA_IN_PROGRESS and DMA_PAUSED if this is implemented in the driver, else 0 💖
• in_flight_bytes — amount of data in bytes cached by the DMA. 🎀

💅 SEE ALSO 💅

Kernel file ./include/linux/dmaengine.h is the home base, and here’s the whole linked-bestie squad — all of them, no skipping 👑

• dma_cookie_t(9)
• enum dma_status(9)
• enum dma_transaction_type(9)
• enum dma_transfer_direction(9)
• struct data_chunk(9)
• struct dma_interleaved_template(9)
• struct dma_vec(9)
• enum dma_ctrl_flags(9)
• enum sum_check_bits(9)
• enum sum_check_flags(9)
• enum dma_desc_metadata_mode(9)
• struct dma_chan_percpu(9)
• struct dma_router(9)
• struct dma_chan(9)
• struct dma_chan_dev(9)
• enum dma_slave_buswidth(9)
• struct dma_slave_config(9)
• enum dma_residue_granularity(9)
• struct dma_slave_caps(9)
• dma_filter_fn(9)
• struct dma_async_tx_descriptor(9)
• enum dmaengine_alignment(9)
• struct dma_slave_map(9)
• struct dma_filter(9)
• struct dma_device(9)
• dmaengine_prep_peripheral_dma_vec(9)
• dmaengine_prep_config_sg_safe(9)
• dmaengine_prep_config_single_safe(9)
• dmaengine_prep_dma_memset(9)
• dmaengine_terminate_all(9)
• dmaengine_terminate_async(9)
• dmaengine_synchronize(9)
• dmaengine_terminate_sync(9)
• dma_async_issue_pending(9)
• dma_async_is_tx_complete(9)
• dma_async_is_complete(9)

Cute sign-off time 🎀 this page comes from source/version ./include/linux, dated October 2026, and it’s struct dma_tx_state(9) — periodt. 💜