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From: Thomas Schimming Thomas on 12 Oct 2006 06:18
I have an USB2.0 device that communicates pieces of data as large bulk
transfers (1-2 MB). On XP I can receive them correctly. As the doc says,
MaximumTransferSize seems practically unlimited.
On Vista RC2 (5744), USBD_CreateConfigurationRequestEx comes back with
MaximumTransferSize set to 0x400000 (no matter what I put there before). This
is too small for my bulk transfer (though the doc doesn't know anything about
such a limit on Vista).

Any way to override this limit?

Any way to split up the transfer without modifying the device's firmware?
I'm not that fluent with the dirty details of USB bulk transfer so I'm not
sure what kind of concepts would apply here?!
From: Alexander Grigoriev on 13 Oct 2006 01:12
You don't have to use such large transfers. Use multiple smaller overlapped
requests.

"Thomas Schimming" <Thomas Schimming(a)discussions.microsoft.com> wrote in
message news:CF42F3FE-724D-401D-BD3B-10F4A84BA9AA(a)microsoft.com...
>I have an USB2.0 device that communicates pieces of data as large bulk
> transfers (1-2 MB). On XP I can receive them correctly. As the doc says,
> MaximumTransferSize seems practically unlimited.
> On Vista RC2 (5744), USBD_CreateConfigurationRequestEx comes back with
> MaximumTransferSize set to 0x400000 (no matter what I put there before).
> This
> is too small for my bulk transfer (though the doc doesn't know anything
> about
> such a limit on Vista).
>
> Any way to override this limit?
>
> Any way to split up the transfer without modifying the device's firmware?
> I'm not that fluent with the dirty details of USB bulk transfer so I'm not
> sure what kind of concepts would apply here?!


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