[Intel-gfx] [PATCH 1/4] introduce intel_ring_buffer structure

[Simon Farnsworth]

On Wednesday 19 May 2010, Eric Anholt <eric.anholt at intel.com> wrote:
> On Wed, 19 May 2010 10:00:10 +0100, Simon Farnsworth 
<simon.farnsworth at onelan.com> wrote:
> > Bear in mind that I don't have to use VAAPI to call your ioctl; I can
> > write evil code that calls it directly. On the other hand, you can't
> > remove the ioctl later - users will want to use older VAAPI versions
> > with new kernels, so that they can upgrade without too much fear of
> > regression.
> 
> OK, now you're going over the top.  The GPU can't schedule[1], is turing
> complete, and you hand it programs.  You can hang it with or without his
> interface.  If you don't want to be able to do that, then don't let
> non-root use the DRI.
> 
Fair enough, and my apologies for going overboard - my intended point is that 
just because VAAPI is the only planned user of this ioctl doesn't mean that 
it's OK to get the userspace/kernel interface wrong.
-- 
Simon Farnsworth
Software Engineer
ONELAN Limited
http://www.onelan.com/