spi_sync_transfer(9)

✨ spi_sync_transfer(9) ✨

okay bestie, sit down, because we're diving into the Kernel API Manual and today's main character is spi_sync_transfer 🎀 this is the synchronous SPI data transfer girlie and honestly she's lowkey iconic. no cap.

---

🌸 NAME 🌸

spi_sync_transfer — synchronous SPI data transfer 💅

---

🦋 SYNOPSIS 🦋

int spi_sync_transfer (struct spi_device *spi , struct spi_transfer
*xfers , unsigned int num_xfers );

like, that's the whole vibe. three args, one return, slay ✨

---

💖 ARGUMENTS 💖

• spi — the device you're exchanging data with! the buddy you're talking to over SPI 🫶
• xfers — an array of spi_transfers. yes, an array, plural energy 👑
• num_xfers — how many items are actually in that xfer array. the count. the receipts. 🔥

---

😴 CONTEXT 😴

can sleep 💀

fr fr remember this one — it can sleep, so don't you dare call it from a context where sleeping is a crime (iykyk). ngl that's important.

---

⭐ DESCRIPTION ⭐

so what does it actually do? it does a synchronous SPI data transfer of the given spi_transfer array. that's the whole thing. it takes your little array of transfers and sends them all off, synchronously, and waits. main character energy 🌈

and if you want the more specific semantics — like the detailed lore, the fine print, the "okay but what does synchronous actually mean here" — go peek at spi_sync. that's where the real details live. this page is just the "here's the array version" announcement 🎀

---

🔥 RETURN 🔥

• zero on success — we love a zero, that's the win condition 🥳
• else a negative error code — 😭 that's the "something went wrong" signal. negative. always negative. no guessing.

not me getting emotional over error codes 💜

---

🧚 SEE ALSO 🧚

okay this list is a whole friend group and you're gonna meet all of them 💅 from the kernel file ./include/linux/spi/spi.h:

• 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)
• spi_controller_xfer_timeout(9)
• struct spi_replaced_transfers(9)
• spi_write(9)
• spi_read(9)
• spi_w8r8(9)
• spi_w8r16(9)
• spi_w8r16be(9)
• struct spi_board_info(9)

like, that's 21 whole entries. obsessed. read them all, don't skip, I'm literally begging 🙈

---

and that's the page bestie!! 💖 this cutie lives at ./include/linux/spi and the version is October 2026, filed under spi_sync_transfer(9) — go forth and transfer your data synchronously, you've got this 🦋✨🍓