USB2.0 descriptor issue for the full speed

Hi all,

I want to prepare a USB2.0 webcam driver which is planed to pass WHQL.
Although it works well, but it fails USB CV test items about device
qualifier and other speed descriptor.

Now I have a question for the full speed descriptor and high spees
descriptor.

How to provide the full speed configure descriptor ? It is declared in
the seperate descriptors or in the device qualifier decriptors and
other speed descriptors?

Does the high speed device qualifier and other speed descriptor need be
declared in the full speed USB descriptor?

Thanks in advance!

Lily

Tim
Wed Sep 13 01:08:02 CDT 2006

"zhong_ping689@hotmail.com" <zhong_ping689@hotmail.com> wrote:
>
>I want to prepare a USB2.0 webcam driver which is planed to pass WHQL.
>Although it works well, but it fails USB CV test items about device
>qualifier and other speed descriptor.
>
>Now I have a question for the full speed descriptor and high spees
>descriptor.
>
>How to provide the full speed configure descriptor ? It is declared in
>the seperate descriptors or in the device qualifier decriptors and
>other speed descriptors?

An other-speed configuration descriptor is specified just like a second
configuration descriptor. So, the order could be:

- device descriptor
- device qualifier descriptor
- configuration descriptor
- other-speed configuration descriptor
- string descriptors

Technically, the order of these isn't important. Drivers can request each
of these individually, and the device should return the corresponding
descriptor.n
--
- Tim Roberts, timr@probo.com
Providenza & Boekelheide, Inc.

zhong_ping689
Wed Sep 13 16:05:54 CDT 2006

Thanks Tim.

You are right, the driver can get all
zhong_ping689@hotmail.com =E5=86=99=E9=81=93=EF=BC=9A

> Hi all,
>
> I want to prepare a USB2.0 webcam driver which is planed to pass WHQL.
> Although it works well, but it fails USB CV test items about device
> qualifier and other speed descriptor.
>
> Now I have a question for the full speed descriptor and high spees
> descriptor.
>
> How to provide the full speed configure descriptor ? It is declared in
> the seperate descriptors or in the device qualifier decriptors and
> other speed descriptors?
>
> Does the high speed device qualifier and other speed descriptor need be
> declared in the full speed USB descriptor?
>=20
> Thanks in advance!
>=20
> Lily

zhong_ping689
Wed Sep 13 16:38:12 CDT 2006

Thanks Tim.

> An other-speed configuration descriptor is specified just like a second
> configuration descriptor. So, the order could be:
>
> - device descriptor
> - device qualifier descriptor
> - configuration descriptor
> - other-speed configuration descriptor
> - string descriptors

I wonder how device respond system request for full speed
configuration, if device is connectted to USB1.1 ready host? Will
device/firmware prepare the full speed related descriptor based on
device qualifier descriptor and other-speed configuration descriptor?
Or get the descriptor from another seperate full speed descriptor copy?

> Technically, the order of these isn't important. Drivers can request each
> of these individually, and the device should return the corresponding
> descriptor.n

You are right, driver can request device descriptor, configuration and
string information individually thru UsbBuildGetDescriptorRequest() , I
am not surehow to get the device qualifier descriptor and other-speed
configuration descriptor.

Best regards,

Lily

Tim
Fri Sep 15 00:07:44 CDT 2006

"zhong_ping689@hotmail.com" <zhong_ping689@hotmail.com> wrote:
>
>I wonder how device respond system request for full speed
>configuration, if device is connectted to USB1.1 ready host? Will
>device/firmware prepare the full speed related descriptor based on
>device qualifier descriptor and other-speed configuration descriptor?
>Or get the descriptor from another seperate full speed descriptor copy?

It's up to the device. Most of the devices I've worked on only have one
device descriptor for each speed.

>> Technically, the order of these isn't important. Drivers can request each
>> of these individually, and the device should return the corresponding
>> descriptor.
>
>You are right, driver can request device descriptor, configuration and
>string information individually thru UsbBuildGetDescriptorRequest() , I
>am not surehow to get the device qualifier descriptor and other-speed
>configuration descriptor.

Why would you want to?

It's no mystery. The device qualifier descriptor is exactly like every
other descriptor. You just specify descriptor type
USB_DEVICE_QUALIFIER_DESCRIPTOR_TYE.
--
- Tim Roberts, timr@probo.com
Providenza & Boekelheide, Inc.