spi_controller_xfer_timeout(9)

✨ spi_controller_xfer_timeout(9) ✨

okay bestie, welcome to the spi_controller_xfer_timeout page from the Kernel API Manual — yes that's the same manual name as the function, iconic of it honestly 🎀

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🌸 NAME 🌸

spi_controller_xfer_timeout — literally just compute a suitable timeout value 💅

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✨ SYNOPSIS ✨

unsigned int spi_controller_xfer_timeout (struct spi_controller *ctlr ,
struct spi_transfer *xfer );

like, it takes two things and hands you back an unsigned int, no cap 🫶

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🦋 ARGUMENTS 🦋

• ctlr — the SPI device (yes, described as a device right there in the original, keep that energy)
• xfer — the transfer descriptor — the little guy describing the transfer you're stressing about

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💜 DESCRIPTION 💜

okay so here's the vibe: this function computes a relevant timeout value for the given transfer. periodt.

the way it does it?? we derive the time that it would take on a single data line, and then we take twice this amount of time — with a minimum of 500ms — to avoid false positives on loaded systems. 💀 like, we're not out here timing out on a busy machine, that's not the mood.

ngl the "minimum of 500ms" bit is the whole personality of this function. slow and steady, bestie. 🧚

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⭐ RETURN ⭐

it returns the transfer timeout value in milliseconds — that's it, that's the gift 🎁

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🔥 SEE ALSO 🔥

kernel file ./include/linux/spi/spi.h (iykyk), plus the whole friend group:

• struct spi_statistics(9)
• struct spi_delay(9)
• struct spi_device(9)
• struct spi_driver(9)
• spi_unregister_driver(9)
• module_spi_driver(9)
• struct spi_controller(9)
• struct spi_res(9)
• struct spi_transfer(9)
• struct spi_message(9)
• spi_message_init_with_transfers(9)
• spi_is_bpw_supported(9)
• spi_bpw_to_bytes(9)
• struct spi_replaced_transfers(9)
• spi_sync_transfer(9)
• spi_write(9)
• spi_read(9)
• spi_w8r8(9)
• spi_w8r16(9)
• spi_w8r16be(9)
• struct spi_board_info(9)

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and that's the whole page, bestie, you ate that 💅✨

sign-off cuteness: this one lives in ./include/linux/spi and it's dated October 2026 — go off, future kernel docs 👑🦋💖