Re: [very-RFC 0/8] TSN driver for the kernel

Richard Cochran
2016-06-14T18:26:21Z

On Tue, Jun 14, 2016 at 11:30:00AM +0200, Henrik Austad wrote:
> So loop data from kernel -> userspace -> kernelspace and finally back to
> userspace and the media application?

Huh? I wonder where you got that idea. Let me show an example of
what I mean.

void listener()
{
int in = socket();
int out = open("/dev/dsp");
char buf[];

while (1) {
recv(in, buf, packetsize);
write(out, buf + offset, datasize);
}
}

See?

> Yes, I know some audio apps "use networking", I can stream netradio, I can
> use jack to connect devices using RTP and probably a whole lot of other
> applications do similar things. However, AVB is more about using the
> network as a virtual sound-card.

That is news to me. I don't recall ever having seen AVB described
like that before.

> For the media application, it should not
> have to care if the device it is using is a soudncard inside the box or a
> set of AVB-capable speakers somewhere on the network.

So you would like a remote listener to appear in the system as a local
PCM audio sink? And a remote talker would be like a local media URL?
Sounds unworkable to me, but even if you were to implement it, the
logic would surely belong in alsa-lib and not in the kernel. Behind
the enulated device, the library would run a loop like the example,
above.

In any case, your patches don't implement that sort of thing at all,
do they?

Thanks,
Richard