spi_split_transfers_maxsize(9)

🌸 spi_split_transfers_maxsize(9) 🌸

okay bestie, welcome to the kernel API manual page for spi_split_transfers_maxsize — yes that's the whole vibe, and yes it's a (9) page, so it's a kernel-internal one, iykyk 💅

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✨ NAME ✨

spi_split_transfers_maxsize — split spi transfers into multiple transfers when an individual transfer exceeds a certain size 🎀

like, if one transfer is doing Too Much, this function chops it up. main character energy for your SPI messages, fr fr.

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🦋 SYNOPSIS 🦋

int spi_split_transfers_maxsize (struct spi_controller *ctlr , struct
spi_message *msg , size_t maxsize );

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💖 ARGUMENTS 💖

• ctlr — the spi_controller for this transfer 👑 (the controller in question, the one running the show)
• msg — the spi_message to transform ✨ (this is the message getting the glow-up)
• maxsize — the maximum when to apply this 🌸 (i.e. the size threshold that triggers the whole thing)

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🌈 DESCRIPTION 🌈

So here's the tea ☕ — this function allocates resources that are automatically freed during the spi message unoptimize phase.

Which means… this function should only be called from optimize_message callbacks. periodt. 💀

Don't try to call it from anywhere else, bestie, the cleanup only happens in that unoptimize phase, and we're not about to leak. nope. not on our watch 🙈

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⭐ RETURN ⭐

status of transformation 💫 (yes, that's the whole return description — she's concise, she's iconic)

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💜 SEE ALSO 💜

the whole friend group, gathered together 🫶 — and it is a long guest list, so buckle up:

• Kernel file ./drivers/spi/spi.c
• __spi_register_driver(9)
• spi_alloc_device(9)
• spi_add_device(9)
• spi_new_device(9)
• spi_unregister_device(9)
• spi_register_board_info(9)
• spi_res_alloc(9)
• spi_res_free(9)
• spi_res_add(9)
• spi_res_release(9)
• spi_finalize_current_transfer(9)
• __spi_pump_messages(9)
• spi_pump_messages(9)
• spi_take_timestamp_pre(9)
• spi_take_timestamp_post(9)
• spi_set_thread_rt(9)
• spi_get_next_queued_message(9)
• spi_finalize_current_message(9)
• spi_queued_transfer(9)
• spi_flush_queue(9)
• of_register_spi_devices(9)
• spi_new_ancillary_device(9)
• devm_spi_new_ancillary_device(9)
• acpi_spi_count_resources(9)
• acpi_spi_device_alloc(9)
• spi_target_abort(9)
• __spi_alloc_controller(9)
• __devm_spi_alloc_controller(9)
• spi_get_gpio_descs(9)
• spi_register_controller(9)
• devm_spi_register_controller(9)
• spi_unregister_controller(9)
• spi_replace_transfers(9)
• spi_split_transfers_maxwords(9)
• spi_set_cs_timing(9)
• spi_setup(9)
• spi_optimize_message(9)
• spi_unoptimize_message(9)
• devm_spi_optimize_message(9)
• spi_async(9)
• spi_sync(9)
• spi_sync_locked(9)
• spi_bus_lock(9)
• spi_bus_unlock(9)
• spi_write_then_read(9)

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ok but seriously: optimize_message callbacks only. the resources get freed in the unoptimize phase, so calling this anywhere else is a no-no 💀💅

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and that's the page, bestie! 🎀 this little love letter lives in the source tree under ./drivers/spi (yeah, the ./drivers/spi directory), dated October 2026 in the footer, and it's filed under the manual name spi_split_transfers_maxsize(9) — go forth and split those transfers responsibly, mwah 🫶💖✨