[Intel-gfx] [PATCH] Revert "drm/i915: Disallow pin ioctl completely for kms drivers"

[Chris Wilson]

On Tue, Nov 25, 2014 at 01:01:39PM +0100, Daniel Vetter wrote:
> On Tue, Nov 25, 2014 at 11:42:56AM +0000, Chris Wilson wrote:
> > This reverts commit c211a47c2c28562f8a3fff9e027be1a3ed9e154a.
> > 
> > This causes an unwarranteed API break for existing and active userspace.
> > 
> > Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> 
> Hm, SNA still seems to be able to cope with this and I really don't see
> the point of keeping this interface going and patching it up. With GEM the
> kernel should be in control of shared resources, letting userspace in to
> the game just leads to tears. And we have them now. Keeping pinning around
> just because we've forgotten to properly disable it was ok with me, but
> fixing it up when it starts to fall apart really isn't.

I strongly disagree. It is a powerful tool, equivalent to mlock(), and
similar to mlock() has its uses.
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre