STRUCT USB_INTERFACE(9)           Host-Side Data Types and Macro          STRUCT USB_INTERFACE(9)



NAME
       struct_usb_interface_cache - long-term representation of a device interface

SYNOPSIS
       struct usb_interface_cache {
         unsigned num_altsetting;
         struct kref ref;
         struct usb_host_interface altsetting[0];
       };

MEMBERS
       num_altsetting
           number of altsettings defined.

       ref
           reference counter.

       altsetting[0]
           variable-length array of interface structures, one for each alternate setting that may
           be selected. Each one includes a set of endpoint configurations. They will be in no
           particular order.

DESCRIPTION
       These structures persist for the lifetime of a usb_device, unlike struct usb_interface
       (which persists only as long as its configuration is installed). The altsetting arrays can
       be accessed through these structures at any time, permitting comparison of configurations
       and providing support for the /proc/bus/usb/devices pseudo-file.

COPYRIGHT
Kernel Hackers Manual 4.8.                 January 2017                   STRUCT USB_INTERFACE(9)