.\" This manpage has been automatically generated by docbook2man 
.\" from a DocBook document.  This tool can be found at:
.\" <http://shell.ipoline.com/~elmert/comp/docbook2X/> 
.\" Please send any bug reports, improvements, comments, patches, 
.\" etc. to Steve Cheng <steve@ggi-project.org>.
.TH "USB_BUFFER_MAP" "9" "17 July 2003" "" ""

.SH NAME
usb_buffer_map \- create DMA mapping(s) for an urb
.SH SYNOPSIS
.sp
\fB
.sp
struct urb * usb_buffer_map  (struct urb * \fIurb\fB);
\fR
.SH "ARGUMENTS"
.TP
\fB\fIurb\fB\fR
urb whose transfer_buffer will be mapped
.SH "DESCRIPTION"
.PP
Return value is either null (indicating no buffer could be mapped), or
the parameter.  URB_NO_DMA_MAP is added to urb->transfer_flags if the
operation succeeds.  If the device is connected to this system through
a non-DMA controller, this operation always succeeds.
.PP
This call would normally be used for an urb which is reused, perhaps
as the target of a large periodic transfer, with \fBusb_buffer_dmasync\fR
calls to synchronize memory and dma state.  It may not be used for
control requests.
.PP
Reverse the effect of this call with \fBusb_buffer_unmap\fR.
.SH "ABOUT THIS DOCUMENT"
.PP
This documentation is free software; you can redistribute
it and/or modify it under the terms of the GNU General Public
License as published by the Free Software Foundation; either
version 2 of the License, or (at your option) any later
version.
.PP
This program is distributed in the hope that it will be
useful, but WITHOUT ANY WARRANTY; without even the implied
warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
See the GNU General Public License for more details.
.PP
You should have received a copy of the GNU General Public
License along with this program; if not, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston,
MA 02111-1307 USA
.PP
For more details see the file COPYING in the source
distribution of Linux.
.PP
If you have comments on the formatting of this manpage, then please contact
Michael Still (mikal@stillhq.com).
.PP
This documentation was generated with kernel version 2.5.71.