usb_add_hcd(9)

💖 usb_add_hcd 💖

okay so bestie, welcome to the Kernel API Manual — this is the usb_add_hcd(9) page and it's literally the "finish getting ready and go live" moment for a USB host controller driver. 🎀

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✨ NAME ✨

usb_add_hcd — finish generic HCD structure initialization and register 🦋

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🌸 SYNOPSIS 🌸

int usb_add_hcd (struct usb_hcd *hcd , unsigned int irqnum , unsigned long irqflags );

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💅 ARGUMENTS 💅

• hcd — the usb_hcd structure to initialize. yes, this one, the main character 👑
• irqnum — Interrupt line to allocate 🔥
• irqflags — Interrupt type flags ✨

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🫶 DESCRIPTION 🫶

So here's the vibe: this function finishes up the remaining parts of generic HCD initialization. Like, the leftovers, but make it iconic. 💫

Specifically it does all of this:

• allocate the buffers of consistent memory 🧚
• register the bus 🌈
• request the IRQ line ⭐
• and call the driver's reset and start routines 🔥

that's it, that's the whole glow-up. no cap. 💅

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👀 SEE ALSO 👀

Kernel file ./drivers/usb/core/hcd.c — plus the whole friend group, fr fr:

• 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_bus_start_enum(9)
• usb_hcd_irq(9)
• usb_hc_died(9)
• usb_create_shared_hcd(9)
• usb_create_hcd(9)
• usb_stop_hcd(9)
• usb_remove_hcd(9)

go read them. all of them. i'll wait. 💖

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mwah 💋 this page came to you straight out of ./drivers/usb/core, dated October 2026 — that's the source, that's the version, and that's the whole entire page. slay. 🎀✨