STRUCT USB_HOST_ENDPOINT(9)

✨ struct usb_host_endpoint(9) ✨

okay so bestie, welcome to the Kernel API Manual 🎀 — today's main character is struct usb_host_endpoint, aka the host-side endpoint descriptor and its queue, all in one iconic little package 💅

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🌸 NAME 🌸

struct usb_host_endpoint — host-side endpoint descriptor and queue ✨

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🦋 SYNOPSIS 🦋

struct usb_host_endpoint {
    struct usb_endpoint_descriptor                  desc;
    struct usb_ss_ep_comp_descriptor                ss_ep_comp;
    struct usb_ssp_isoc_ep_comp_descriptor          ssp_isoc_ep_comp;
    struct usb_eusb2_isoc_ep_comp_descriptor        eusb2_isoc_ep_comp;
    struct list_head                urb_list;
    void *hcpriv;
    struct ep_device                *ep_dev;
    unsigned char *extra;
    int extralen;
    int enabled;
    int streams;
 };

like, look at her. she's got range 💖

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💜 Members 💜

• desc — the descriptor for this endpoint, and heads up: wMaxPacketSize is in native byteorder 🧚 (yes, that matters, don't come for me)
• ss_ep_comp — the SuperSpeed companion descriptor for this endpoint ⚡
• ssp_isoc_ep_comp — the SuperSpeedPlus isoc companion descriptor for this endpoint 🔥
• eusb2_isoc_ep_comp — the eUSB2 isoc companion descriptor for this endpoint 🦋
• urb_list — urbs queued to this endpoint; this one's maintained by usbcore, so hands off bestie 🙈
• hcpriv — for use by HCD; typically holds the hardware dma queue head (QH) with one or more transfer descriptors (TDs) per urb. It must be preserved by core while BW is allocated for the endpoint 👑 (read that again, it's giving important)
• ep_dev — the ep_device for sysfs info 🎀
• extra — descriptors following this endpoint in the configuration 🌈
• extralen — how many bytes of "extra" are actually valid ⭐
• enabled — URBs may be submitted to this endpoint ✅
• streams — number of USB-3 streams allocated on the endpoint 🌊

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🫶 Description 🫶

USB requests are always queued to a given endpoint — and that endpoint is identified by a descriptor within an active interface in a given USB configuration. periodt. 💅

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🌟 SEE ALSO 🌟

Kernel file ./include/linux/usb.h — and honestly the whole friend group showed up:

• 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_interface_claimed(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)

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ngl bestie, if you got this far you're lowkey a kernel girlie now 💀👑

and that's the tea — this page lives in ./include/linux, stamped October 2026, and it's the struct usb_host_endpoint(9) era. mwah 💋✨