usb_root_hub_lost_power(9)

📦 version 7.3.1, in nixpkgs unstable

✨ usb_root_hub_lost_power(9) ✨

okay so bestie, this one's a Kernel API Manual moment, and it's honestly giving "quietly important" energy 💅 it's all about what happens when a root hub loses its Vbus power and somebody has to deal with the fallout. no cap.

🎀 NAME 🎀

usb_root_hub_lost_power — the function the HCD calls when the root hub lost Vbus power 🫶

🌸 SYNOPSIS 🌸

void usb_root_hub_lost_power (struct usb_device *rhdev );

🦋 ARGUMENTS 🦋

  • rhdev — the struct usb_device for the root hub, literally the main character here 👑

💖 DESCRIPTION 💖

so here's the vibe: the USB host controller driver calls this function when its root hub is resumed and Vbus power has been interrupted, or the controller has been reset. 😭 messy, i know.

what the routine does is mark rhdev as having lost power. periodt. that's the whole assignment, and it does it flawlessly 💅

then, when the hub driver is resumed, it will take notice 👀 and carry out power-session recovery for all the "USB-PERSIST"-enabled child devices. the others? not so lucky — they will be disconnected 💀

ngl bestie, that last bit is the important part: if a device isn't "USB-PERSIST"-enabled, it does not get recovered. it gets disconnected. no exceptions mentioned, so don't go making any up 🙈

🔥 SEE ALSO 🔥

and now for the friend group — the Kernel file ./drivers/usb/core/hub.c plus literally this whole roster of related functions, all iconic in their own right:

and that's the whole page, bestie, we ate and left zero crumbs 💖 this lil gem lives in ./drivers/usb/core, it's dated October 2026, and it comes from the Kernel API Manual — so go forth and be the person who actually knows what usb_root_hub_lost_power(9) does 🌈✨🍓

📦 where this page comes from