Subject: Re: proposed change to ugen to enable USRP to work
To: Joanne M Mikkelson <>
From: Iain Hibbert <>
List: tech-kern
Date: 05/09/2006 10:12:18
On Tue, 8 May 2006, Joanne M Mikkelson wrote:

> The lack of write support in ugen isn't the only difficulty with
> using isochronous transfers.  The ehci driver does not implement
> isochronous transfers at all, so that would have to addressed in
> addition to using the code from the PR.

Actually, I have been working with isochronous transfers lately and there
seem to be problems in the current uhci support also.

> and perhaps you were thinking there would a different behavior for
> mmapped buffers in ugen,

Yes, was just throwing up the concept really, since your proposal made no
mention, and it seems that it would be more efficient for a continuous
data stream which I think is what you get with USRP (and why they used it
for audio).

>                           but I don't think we want to force users of
> continuous read mode to keep up or risk losing data.

well you kind of have to plan for that anyway since buffer space is