'\" t
.\"     Title: usb_clear_halt
.\"    Author: [FIXME: author] [see http://docbook.sf.net/el/author]
.\" Generator: DocBook XSL Stylesheets v1.79.1 <http://docbook.sf.net/>
.\"      Date: June 2017
.\"    Manual: USB Core APIs
.\"    Source: Kernel Hackers Manual 4.9.30
.\"  Language: English
.\"
.TH "USB_CLEAR_HALT" "9" "June 2017" "Kernel Hackers Manual 4\&.9\&." "USB Core APIs"
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.SH "NAME"
usb_clear_halt \- tells device to clear endpoint halt/stall condition
.SH "SYNOPSIS"
.HP \w'int\ usb_clear_halt('u
.BI "int usb_clear_halt(struct\ usb_device\ *\ " "dev" ", int\ " "pipe" ");"
.SH "ARGUMENTS"
.PP
\fIdev\fR
.RS 4
device whose endpoint is halted
.RE
.PP
\fIpipe\fR
.RS 4
endpoint
\(lqpipe\(rq
being cleared
.RE
.SH "CONTEXT"
.PP
!in_interrupt ()
.SH "DESCRIPTION"
.PP
This is used to clear halt conditions for bulk and interrupt endpoints, as reported by URB completion status\&. Endpoints that are halted are sometimes referred to as being
\(lqstalled\(rq\&. Such endpoints are unable to transmit or receive data until the halt status is cleared\&. Any URBs queued for such an endpoint should normally be unlinked by the driver before clearing the halt condition, as described in sections 5\&.7\&.5 and 5\&.8\&.5 of the USB 2\&.0 spec\&.
.PP
Note that control and isochronous endpoints don\*(Aqt halt, although control endpoints report
\(lqprotocol stall\(rq
(for unsupported requests) using the same status code used to report a true stall\&.
.PP
This call is synchronous, and may not be used in an interrupt context\&.
.SH "RETURN"
.PP
Zero on success, or else the status code returned by the underlying
\fBusb_control_msg\fR
call\&.
.SH "COPYRIGHT"
.br