Subject: Re: proposed change to ugen to enable USRP to work
To: Hans Petter Selasky <>
From: Greg Troxel <>
List: tech-kern
Date: 05/03/2006 15:55:33
The USRP uses bulk transfers, and avoids large reads to keep latencies

  I think the problem you experience entirely lies within the file

Agreed; perhaps that was too implicit.  The intent was to modify
ugen.c to have multiple reads going at once.  But, this is different
semantics than ugen currently has, where bus transactions only happen
when read is called.  So we need something clean and backwards
compatible in NetBSD that's usable by the USRP user-space library.

The ugen.c on your website looks quite different from NetBSD-current's
ugen.c.  Can you explain the lineage and differences?

        Greg Troxel <>