usb_bus_start_enum(9)

💖 NAME 💖

usb_bus_start_enum — start immediate enumeration (for OTG). Welcome to the usb_bus_start_enum(9) page from the Kernel API Manual, bestie ✨.

🌸 SYNOPSIS 🌸

The whole signature is right here, and yes, we’re keeping the spacing exactly as given 🫶:

int usb_bus_start_enum (struct usb_bus *bus , unsigned port_num );

🎀 ARGUMENTS 🎀

• bus — the bus. It must use hcd framework, no cap 💅.
• port_num — the 1-based number of the port; usually bus->otg_port 🦋.

⚡ CONTEXT ⚡

atomic — like, that’s the context, bestie. She’s atomic 😭.

🦋 DESCRIPTION 🦋

Starts enumeration, with an immediate reset followed later by hub_wq identifying and possibly configuring the device. This is needed by OTG controller drivers, where it helps meet HNP protocol timing requirements for starting a port reset. It’s giving “reset now, let hub_wq handle the identify-and-maybe-configure part later” energy 💖.

⭐ RETURN ⭐

0 if successful. That’s the return tea, bestie ✅.

🌈 SEE ALSO 🌈

Kernel file ./drivers/usb/core/hcd.c and the whole friend group:

• ascii2desc(9)
• rh_string(9)
• usb_bus_init(9)
• usb_register_bus(9)
• usb_deregister_bus(9)
• register_root_hub(9)
• usb_calc_bus_time(9)
• usb_hcd_link_urb_to_ep(9)
• usb_hcd_check_unlink_urb(9)
• usb_hcd_unlink_urb_from_ep(9)
• usb_hcd_giveback_urb(9)
• usb_hcd_alloc_bandwidth(9)
• usb_hcd_reset_endpoint(9)
• usb_alloc_streams(9)
• usb_free_streams(9)
• usb_hcd_resume_root_hub(9)
• usb_hcd_irq(9)
• usb_hc_died(9)
• usb_create_shared_hcd(9)
• usb_create_hcd(9)
• usb_stop_hcd(9)
• usb_add_hcd(9)
• usb_remove_hcd(9)

Source/version vibe: ./drivers/usb/core; date stamp: October 2026. Bye bestie, go start that enumeration 💖✨