[Nouveau] making 0.0.16 into 1.0.0

Dave Airlie airlied at gmail.com
Thu Mar 4 17:23:46 PST 2010

So with all this ongoing Linus crap I'm going to be brave and ask for
reasons why
0.0.16 kernel API can't become 1.0.0.

All old userspace compatibility is gone.
No more UMS cruft to support.
Something can be shipped on distros at last, people get to use the driver.
3D drivers exist and use the interface, there is an investment in these already.

Reasons against: (I'm making these up, feel free ack/nack/flesh
out/add more etc).
We haven't finished 3D drivers yet so the interface may still need changes?
TTM sucks?
Userspace command-submission for ever?
I don't like versioning anything ever?

So my current answers to my list of cons is:

Adding new faster interfaces for 3D drivers shouldn't be a major problem, if its
just a matter of making the current APIs saner.

If you are going to write a UCS/non-TTM driver you are going to have to do
major changes all over the stack, in theory a kernel CONFIG option to enable
version 2 of the interface and drop version 1 would be an option at that time.
Or even a boot option to select between which one you want. I would
forsee a UCS/non-TTM driver needing to rewrite quite a lot of userspace,
in fact probably all of it. I haven't seen anyone actually start or
commit to working
on such a beast, and I'd reckon its probably a 1-2 year job, GEM took over a
year and it was arguably simpler. I'm not seeing the point of sitting
in a holding
pattern for that length of time just in case its better. The future is
always going
to be better.

As for the I don't like versioning argument, well that really doesn't
need addressing,
you have to do version stuff to ship it, if the project as a whole
decides they don't
see a need to ever ship the code, then so be it.


More information about the Nouveau mailing list