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Re: [Discuss-gnuradio] proposed change to ugen to enable USRP to work we
From: |
Daniel O'Connor |
Subject: |
Re: [Discuss-gnuradio] proposed change to ugen to enable USRP to work well on NetBSD |
Date: |
Thu, 4 May 2006 11:58:34 +0930 |
User-agent: |
KMail/1.9.1 |
On Thursday 04 May 2006 03:30, Greg Troxel wrote:
> Joanne has written a proposal to modify NetBSD's ugen(4) to get good
> performance for the USRP. We'd like feedback about the technical
> approach. (Once we have it working, the changes will be commited to
> NetBSD-current.)
>
> http://acert.ir.bbn.com/downloads/adroit/NetBSD-USB-continuous.pdf
I think the ioctl would be the cleanest approach - it would not break any
existing software.
I wonder if it may be possible to have the ioctl specify a packet size and the
kernel will keep reading data of that packet size into the buffer as long as
it isn't full. I think that would give you something that looks a lot closer
to a normal device (normal being "what the unix IO model expects" :)
It would be nice if you could do a readv() and then poll/kqueue/select/signal
to see when an iovec has been filled, however I suspect that would require
severe modification of the kernel internals.
--
Daniel O'Connor software and network engineer
for Genesis Software - http://www.gsoft.com.au
"The nice thing about standards is that there
are so many of them to choose from."
-- Andrew Tanenbaum
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