AMD GPU new API for new module

[Daniel Vetter]

On Wed, Oct 8, 2014 at 6:00 PM, Jerome Glisse <j.glisse at gmail.com> wrote:
>
> struct radeon_ioctl {
>         u32     version;
>         u32     size;
> };

How is this any different from just another ioctl multiplexer and why
can't we just add a new version if an ioctl needs to be revised? E.g.
in i915 we've just added execbuf2 and within execbuf2 there's tons of
flags to enable/disable code. I don't see what a version field buys us
on top of having flags fields and just creating a new ioctl if that
gets too fuzzy. In the end you still have to keep all the old crap
working, and imo that's easier to do long-term if you don't make it
too easy to add new interfaces.

Also, the size is encoded in the ioctl itself and like Rob said the
core takes care of properly zero-filling this.
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch