[wdmaudiodev] Re: *****SPAM***** MaxTransferSize and Control Endpoint

  • From: timr@xxxxxxxxx
  • To: wdmaudiodev@xxxxxxxxxxxxx
  • Date: Sun, 21 Oct 2007 20:24:20 -0700

On Wed, Oct 10, 2007 at 07:36:41AM -0700, wade wrote:
> 
> Does anyone know if there is a way to set the MaxTransferSize for the
> control Endpoint using USBD?  I'm successfully selecting an interface
> with the desired MaxTransferSize but when I do a Control-Write with
> a MaxTransferSize-sized packet I'm get an int3 in the IOCallDriver()
> call and a STATUS_INVALID_PARAMETER return from the call.
>    
>   The MaxTransferSize of the selected interface is 8204 bytes but I'm 
> only able to send about 4k without the int3.  

I don't know what you mean by that sentence.  Interfaces do not have
a max transfer size.  Pipes have a MaximumTransferSize, although Windows 
XP ignores it.

However:
    http://support.microsoft.com/kb/832430

The control endpoint has a maximum transfer size of 4k, and there's 
nothing you can do to change that.  Remember that the control endpoint
on a high-speed device can only transfer 64 bytes at a time, so even
a 4k transfer is a lot of consecutive packets.

You will have to chop it into smaller pieces on your own.
-- 
Tim Roberts, timr@xxxxxxxxx
Providenza & Boeklheide, Inc.
******************

WDMAUDIODEV addresses:
Post message: mailto:wdmaudiodev@xxxxxxxxxxxxx
Subscribe:    mailto:wdmaudiodev-request@xxxxxxxxxxxxx?subject=subscribe
Unsubscribe:  mailto:wdmaudiodev-request@xxxxxxxxxxxxx?subject=unsubscribe
Moderator:    mailto:wdmaudiodev-moderators@xxxxxxxxxxxxx

URL to WDMAUDIODEV page:
http://www.wdmaudiodev.com/

Other related posts:

  • » [wdmaudiodev] Re: *****SPAM***** MaxTransferSize and Control Endpoint