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[Qemu-devel] [PATCH v2 0/4]usb: implement Interface Association Descript
From: |
Brad Hards |
Subject: |
[Qemu-devel] [PATCH v2 0/4]usb: implement Interface Association Descriptor support |
Date: |
Sun, 3 Apr 2011 15:33:17 +1000 |
These descriptors are covered in Section 9.6.4 of the USB 3.0 spec,
but there is a better description in the Intel IAD whitepaper
(www.usb.org/developers/whitepapers/iadclasscode_r10.pdf).
The short version is that IAD is an extra descriptor type that appears before
a group (two or more) interface descriptors, that explains which interface
descriptors make up a virtual device. So it could look like:
Config Desc
IAD#0
Iface#0
Iface#1
Iface#2
IAD#1
Iface#3
Iface#4
[Check the diagram in the Intel IAD whitepaper if that makes no sense]
The implementation basically introduces the concept of a grouped of
interfaces (with an IAD header), and support for sending it to the
device.
The intended use for this is USB Video class devices, which have a
Control interface and Streaming interface that are a single logical
device.
Changes v2 (from v1):
- Added Signed-off-by, per CODING_STYLE
- Fixed bug in altsetting handling (.nif needed instead of .bNumInterfaces)
- Fixed some whitespace and line-length problems indicated by checkstyle.pl
Diffstat:
usb-desc.c | 52 +++++++++++++++++++++++++++++++++++++++++++++++++---
usb-desc.h | 20 ++++++++++++++++++++
usb-hid.c | 3 +++
usb-hub.c | 1 +
usb-msd.c | 2 ++
usb-serial.c | 1 +
usb-wacom.c | 1 +
usb.h | 2 ++
8 files changed, 79 insertions(+), 3 deletions(-)
- [Qemu-devel] [PATCH v2 0/4]usb: implement Interface Association Descriptor support,
Brad Hards <=