'\" t
.\"     Title: struct usb_interface_cache
.\"    Author: [FIXME: author] [see http://docbook.sf.net/el/author]
.\" Generator: DocBook XSL Stylesheets v1.79.1 <http://docbook.sf.net/>
.\"      Date: January 2017
.\"    Manual: Host-Side Data Types and Macros
.\"    Source: Kernel Hackers Manual 4.8.15
.\"  Language: English
.\"
.TH "STRUCT USB_INTERFACE" "9" "January 2017" "Kernel Hackers Manual 4\&.8\&." "Host-Side Data Types and Macro"
.\" -----------------------------------------------------------------
.\" * Define some portability stuff
.\" -----------------------------------------------------------------
.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
.\" http://bugs.debian.org/507673
.\" http://lists.gnu.org/archive/html/groff/2009-02/msg00013.html
.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
.ie \n(.g .ds Aq \(aq
.el       .ds Aq '
.\" -----------------------------------------------------------------
.\" * set default formatting
.\" -----------------------------------------------------------------
.\" disable hyphenation
.nh
.\" disable justification (adjust text to left margin only)
.ad l
.\" -----------------------------------------------------------------
.\" * MAIN CONTENT STARTS HERE *
.\" -----------------------------------------------------------------
.SH "NAME"
struct_usb_interface_cache \- long\-term representation of a device interface
.SH "SYNOPSIS"
.sp
.nf
struct usb_interface_cache {
  unsigned num_altsetting;
  struct kref ref;
  struct usb_host_interface altsetting[0];
};  
.fi
.SH "MEMBERS"
.PP
num_altsetting
.RS 4
number of altsettings defined\&.
.RE
.PP
ref
.RS 4
reference counter\&.
.RE
.PP
altsetting[0]
.RS 4
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\&.
.RE
.SH "DESCRIPTION"
.PP
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\&.
.SH "COPYRIGHT"
.br