__dma_request_channel(9)

💖 NAME 💖

okay bestie, so this is the page for __dma_request_channel from the Kernel API Manual, and its whole job is literally to try to allocate an exclusive channel. That's the name, that's the vibe, no cap. 💅

✨ SYNOPSIS ✨

the signature is giving main-character energy:

struct dma_chan * __dma_request_channel (const dma_cap_mask_t *mask , dma_filter_fn fn , void *fn_param , struct device_node *np );

🎀 ARGUMENTS 🎀

• mask — the capabilities that the channel must satisfy. it's the vibe check the channel has to pass, fr fr.
• fn — an optional callback used to disposition the available channels. lowkey the filter bestie.
• fn_param — an opaque parameter that gets passed straight to dma_filter_fn. iykyk.
• np — the device node to look for DMA channels. that's the hunting ground. 🦋

🌸 DESCRIPTION 🌸

Returns a pointer to the appropriate DMA channel on success, or NULL. That's it. That's the tea. 💖

👑 SEE ALSO 👑

Kernel file ./drivers/dma/dmaengine.c — the source/version main character — plus this whole group chat of friends:

• dev_to_dma_chan(9)
• struct dma_chan_tbl_ent(9)
• dma_chan_is_local(9)
• min_chan(9)
• dma_channel_rebalance(9)
• balance_ref_count(9)
• dma_chan_get(9)
• dma_chan_put(9)
• dma_find_channel(9)
• dma_issue_pending_all(9)
• dma_get_slave_channel(9)
• dma_request_chan(9)
• dma_request_chan_by_mask(9)
• devm_dma_request_chan(9)
• dmaengine_get(9)
• dmaengine_put(9)
• dma_async_device_register(9)
• dma_async_device_unregister(9)
• dmaenginem_async_device_register(9)
• dma_wait_for_async_tx(9)
• dma_run_dependencies(9)

shoutout to ./drivers/dma (the source/version) and October 2026 (the date) — iconic, periodt. 🫶💋