usb_interface_claimed(9)

💅 usb_interface_claimed(9) — a.k.a. the "is this interface taken?" check

okay so bestie, welcome to the Kernel API Manual page for usb_interface_claimed — yes it's a mouthful, yes it's iconic, and yes we're gonna get through it together 🫶

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✨ NAME ✨

usb_interface_claimed — literally returns true iff an interface is claimed. that's it. that's the whole vibe check 💅

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✨ SYNOPSIS ✨

int usb_interface_claimed (struct usb_interface *iface );

like, one function, one argument, zero drama 🎀

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✨ ARGUMENTS ✨

• iface — the interface being checked, aka the main character of this whole operation 👑

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✨ RETURN ✨

here's the tea 🍓: it returns true (nonzero) iff the interface is claimed, and false (zero) otherwise. no in-between, no "it's complicated", just yes or no. slay.

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✨ NOTE ✨ 🌸

okay this part is important, pay attention bestie 😭

Callers must own the driver model's usb bus readlock. So the good news: driver probe entries don't need extra locking (they're already covered, no cap). The "well actually" news: other call contexts may need to explicitly claim that lock. fr fr, don't skip this one 🙈

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✨ SEE ALSO ✨ 🦋

• Kernel file ./include/linux/usb.h
• struct usb_host_endpoint(9)
• struct usb_interface(9)
• usb_set_intfdata(9)
• struct usb_interface_cache(9)
• struct usb_host_config(9)
• struct usb_device(9)
• usb_hub_for_each_child(9)
• usb_make_path(9)
• USB_DEVICE(9)
• USB_DEVICE_VER(9)
• USB_DEVICE_INTERFACE_CLASS(9)
• USB_DEVICE_INTERFACE_PROTOCOL(9)
• USB_DEVICE_INTERFACE_NUMBER(9)
• USB_DEVICE_INFO(9)
• USB_INTERFACE_INFO(9)
• USB_DEVICE_AND_INTERFACE_INFO(9)
• USB_VENDOR_AND_INTERFACE_INFO(9)
• struct usb_driver(9)
• struct usb_device_driver(9)
• struct usb_class_driver(9)
• module_usb_driver(9)
• struct urb(9)
• usb_fill_control_urb(9)
• usb_fill_bulk_urb(9)
• usb_fill_int_urb(9)
• usb_urb_dir_in(9)
• usb_urb_dir_out(9)
• struct usb_sg_request(9)

like, an entire friend group of cross-references, we love to see it 🌈

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and that's the page!! 💖 this lil beauty lives in ./include/linux and the version/date on it is October 2026 — so mark your calendars, bestie 🎀✨👑