Re: comedi in the main kernel.org tree?

On Tuesday 22 August 2006 02:20 am, Greg KH wrote:
> On Mon, Aug 21, 2006 at 11:05:15PM -0700, David Schleef wrote:
> > On Mon, Aug 21, 2006 at 10:28:38PM -0700, Greg KH wrote:
> > > "months"?  So I can't just grab your current tree and add it to the
> > > main build system now?  That doesn't sound like something your
> > > current users would probably like to hear :)
> >
> > Actually, I'd be more likely to hear "So does this mean you're no
> > longer supporting 2.6.14?  That's the only version I can use with
> > RTAI."  People that want to compile Comedi as part of the kernel
> > already use Ian Abbott's patches.
> >
> > There are more important things to do in Comedi than move it into
> > the kernel source.  Fixing PCMCIA support for current kernels
> > comes to mind.  Updating all the drivers to be vaguely 2.6-like
> > is another.
>
> Well, that's why I'm interested in that.  I'm starting to see reports of
> users that are using Comedi with udev and trying to get it to work
> properly.  Comedi needs to intregrate with the driver model a bit better
> in order for them to use udev to name their devices in a persistant
> manner.
>
> I'll help do this work, but I would like to get the code into the main
> kernel source tree first, as it's easier for me to work on things like
> this that way.
>
> thanks,
>
> greg k-h

My inclination is to move into main tree sooner rather than later, mostly 
because I'd like to dump the burden of supporting a continuum of kernel 
interfaces.  I definitely feel a reluctance to support newer kernel 
features due to the overhead of making sure the changes don't break things 
on older kernels, and having to take on an increased burden of assuring 
compatibility for a wider swath of the kernel API.  I think in the long 
run, comedi would be in better shape if we could redirect some of our 
limited developer resources away from backward compatibility.

People wanting to use older kernels wouldn't be completely hosed, since if 
5 years from now someone wants to run comedi with a 2.6.20 kernel, they 
would at least be able to try the version that shipped in the 2.6.20 
kernel.  Currently, if support for an older kernel gets dropped from the 
latest comedi release, it's not clear which old version X of comedi is the 
best to use for old kernel version Y.

That said, I don't feel strongly enough about this to try and ram this down 
everyone's throat.  So if Dave or Ian or enough interested parties are set 
against it I'll let it drop.  But having a kernel insider willing to help 
ease the pain of moving into the main kernel tree seems like a good 
opportunity.

It's a little hazy to me how RTAI support is going to work though.  Are we 
going to be able to put #ifdef'd RTAI support code in the main kernel 
tree?

-- 
Frank