usb_alloc_dev(9)

💖 usb_alloc_dev(9) 💖

okay so bestie, welcome to this page from the Kernel API Manual — it's all about usb_alloc_dev(9), the usb device constructor, and it's very much usbcore-internal business. 🧚✨

🌸 NAME 🌸

usb_alloc_dev — usb device constructor (usbcore-internal)

🎀 SYNOPSIS 🎀

struct usb_device * usb_alloc_dev (struct usb_device *parent , struct usb_bus *bus , unsigned port1 );

🦋 ARGUMENTS 🦋

• parent — the hub to which the device is connected; null to allocate a root hub. 🌈
• bus — the bus used to access the device. 🚌
• port1 — one-based index of the port; ignored for root hubs. 🔢

💅 CONTEXT 💅

task context, might sleep. 😴 So yeah, this one can catch some z's — it's giving sleepy-time energy, lowkey.

🔥 DESCRIPTION 🔥

The way that only hub drivers — including virtual root hub drivers for host controllers — should ever call this is so real. 👑 No cap: this one is for the hub-driver girlies, not everybody.

And bestie, this call may not be used in a non-sleeping context. 🚨 Fr fr, do not pop this in a non-sleeping context, periodt. 💀

⭐ RETURN ⭐

On success, you get a pointer to the allocated usb device. 🫶 On failure, it's NULL. 😭

🌟 SEE ALSO 🌟

Kernel file: ./drivers/usb/core/usb.c 📁

• usb_find_common_endpoints(9)
• usb_find_common_endpoints_reverse(9)
• usb_find_endpoint(9)
• usb_check_bulk_endpoints(9)
• usb_check_int_endpoints(9)
• usb_find_alt_setting(9)
• usb_ifnum_to_if(9)
• usb_altnum_to_altsetting(9)
• usb_find_interface(9)
• usb_for_each_dev(9)
• usb_release_dev(9)
• usb_get_dev(9)
• usb_put_dev(9)
• usb_get_intf(9)
• usb_put_intf(9)
• usb_intf_get_dma_device(9)
• usb_lock_device_for_reset(9)
• usb_get_current_frame_number(9)
• usb_alloc_coherent(9)
• usb_free_coherent(9)
• usb_alloc_noncoherent(9)
• usb_free_noncoherent(9)
• usb_endpoint_max_periodic_payload(9)
• usb_endpoint_is_hs_isoc_double(9)

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mwah 💋 signing off from ./drivers/usb/core — October 2026 — usb_alloc_dev(9) 🫶✨