fsl_chan_set_request_count(9)

💅 fsl_chan_set_request_count (9) — Kernel API Manual

okay so bestie, welcome to the Freescale DMA channel corner of the kernel, because we're about to talk about setting the DMA request count for external control ✨

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🌸 NAME 🌸

fsl_chan_set_request_count — Set DMA Request Count for external control 🎀

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🦋 SYNOPSIS 🦋

void fsl_chan_set_request_count (struct fsldma_chan *chan , int size );

like, that's the whole signature. void return, two args, no cap 💅

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⭐ ARGUMENTS ⭐

• chan — the Freescale DMA channel, your main character here 👑
• size — Number of bytes to transfer in a single request 🍓

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💖 DESCRIPTION 💖

so here's the vibe: the Freescale DMA channel can be controlled by the external signal DREQ#. and the DMA request count is literally how many bytes are allowed to transfer before pausing the channel — after which a new assertion of DREQ# resumes channel operation. it's giving "traffic light for bytes" 🚦✨

A size of 0 disables external pause control. and the maximum size is 1024 — so don't come in there with a bigger number, that's the ceiling, periodt 🔥

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👑 SEE ALSO 👑

Kernel file ./drivers/dma/fsldma.c plus the whole friend group 🫶:

• fsl_chan_set_src_loop_size(9)
• fsl_chan_set_dst_loop_size(9)
• fsl_chan_toggle_ext_pause(9)
• fsl_chan_toggle_ext_start(9)
• fsl_dma_free_descriptor(9)
• fsl_dma_alloc_descriptor(9)
• fsldma_clean_completed_descriptor(9)
• fsldma_run_tx_complete_actions(9)
• fsldma_clean_running_descriptor(9)
• fsl_chan_xfer_ld_queue(9)
• fsldma_cleanup_descriptors(9)
• fsl_dma_alloc_chan_resources(9)
• fsldma_free_desc_list(9)
• fsl_dma_free_chan_resources(9)
• fsl_dma_memcpy_issue_pending(9)
• fsl_tx_status(9)

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💀 reminder bestie: 0 = external pause control off, 1024 = the max. anything else is a vibe check you might fail, so keep it in range 🙈

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and that's the page!! 🌈 brought to you from ./drivers/dma, dated October 2026, signed off by fsl_chan_set_request_count(9) itself — slay, go set some request counts, ily 🎀💜