usb_bulk_msg_killable(9)

📦 version 7.3.1, in nixpkgs unstable

💅 usb_bulk_msg_killable — from the Kernel API Manual, bestie

Okay so picture this: you're in the kernel, you've got a USB device, and you need to send a bulk message and wait for it to finish — but with the option to get interrupted like a normal, killable little task. That's the whole vibe of usb_bulk_msg_killable, and honestly? Iconic. ✨

🦋 NAME

usb_bulk_msg_killable — builds a bulk urb, sends it off, and waits for completion in a killable state. No cap, that's literally what it does. 🎀

🌸 SYNOPSIS

int usb_bulk_msg_killable (struct usb_device *usb_dev , unsigned int
pipe , void *data , int len , int *actual_length , int timeout );

🍓 ARGUMENTS

  • usb_dev — pointer to the usb device you're sending the message to 🫶
  • pipe — the endpoint "pipe" to send the message to
  • data — pointer to the data to send
  • len — length in bytes of the data to send
  • actual_length — pointer to a location to put the actual length transferred in bytes (yes, actual — because sometimes you ask for a lot and only part of it goes through, iykyk)
  • timeout — time in msecs to wait for the message to complete before timing out (if <= 0, the wait is as long as possible 💀)

🧚 CONTEXT

task context, might sleep. So like… don't be weird about it. 😴

👑 DESCRIPTION

This function is just like usb_blk_msg, except that it waits in a killable state and there is no limit on the timeout length. That's the tea. 🫖 Two whole differences, both of them lowkey huge: killable wait, unlimited timeout. Slay.

🔥 RETURN

If successful, 0. Otherwise a negative error number. The number of actual bytes transferred will be stored in the actual_length parameter. So even when it's giving failure energy, you still get the byte count. Iconic behavior honestly. 💖

🌈 SEE ALSO

Kernel file ./drivers/usb/core/message.c, plus the whole friend group:

bestie reminder: it waits in a killable state, so your task can absolutely get yeeted mid-wait. that's a feature, not a bug 💅

And that's the page, fr fr — brought to you by the fine folks over at ./drivers/usb/core, dated October 2026, filed under usb_bulk_msg_killable(9). Go forth and bulk-msg responsibly, bestie 🌟🎀

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