write_packet(9)

📦 version 7.3.1, in nixpkgs unstable

💅 write_packet(9) — like, the transfer-one-packet one 💖

okay bestie so this is a page from the Kernel API Manual (write_packet(9)), and honestly? It's a little shortie but she's got range. Let's get into it ✨

🌸 NAME 🌸

write_packet — move exactly 1 packet from a request into an IN endpoint. one. single. packet. she's not greedy 🎀

🦋 SYNOPSIS 🦋

int write_packet (struct pxa_ep *ep , struct pxa27x_request *req ,
unsigned int max );

✨ ARGUMENTS ✨

  • ep — the pxa physical endpoint, iykyk. This is the actual hardware-side endpoint, not a vibe 💅
  • req — the usb request. this is where the bytes are coming from 🫶
  • max — the max bytes that can fit into the endpoint. like a little suitcase with a strict capacity, no cap 🧳

🌈 DESCRIPTION 🌈

So here's the whole plot: write_packet takes bytes from the usb request (req) and transfers them into the physical endpoint (ep). That's it. That's the job. main character energy from start to finish 👑

And literally — if there are no bytes to transfer, it doesn't write anything to the physical endpoint. Nothing. Zero. She simply does not participate 🙈 (respect, honestly.)

The return value? Returns how many bytes were actually transferred. So like, the actual receipts, not the vibes — check the number, bestie, it's the truth 📊

lowkey important: the return is how many were actually transferred, not how many you hoped for. read it. trust it. 💀

🍓 SEE ALSO 🍓

Big friend-group energy here — the kernel file ./drivers/usb/gadget/udc/pxa27x_udc.c is where all of these live, and here's the whole squad in order, fr fr:

(kind of iconic that the list is that long and every single one is (9). a whole sorority 💜)

okay that's the page!! shoutout to the source in ./drivers/usb/gadget/udc and the October 2026 date — slay, documented, timestamped, periodt 📅💅 hope u understood it bestie, mwah 🫶💖

📦 where this page comes from