[Intel-gfx] [PATCH] drm/i915: Deny wrapping an userptr into a framebuffer

[Daniel Vetter]

On Tue, Oct 13, 2015 at 03:00:18PM +0100, Tvrtko Ursulin wrote:
> 
> On 13/10/15 14:22, Chris Wilson wrote:
> >Pinning a userptr onto the hardware raises interesting questions about
> >the lifetime of such a surface as the framebuffer extends that life
> >beyond the client's address space. That is the hardware will need to
> >keep scanning out from the backing storage even after the client wants
> >to remap its address space. As the hardware pins the backing storage,
> >the userptr becomes invalid and this raises a WARN when the clients
> >tries to unmap its address space. The situation can be even more
> >complicated when the buffer is passed between processes, between a
> >client and display server, where the lifetime and hardware access is
> >even more confusing. Deny it.
> 
> Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>

Reviewed-by: Daniel Vetter <daniel.vetter at ffwll.ch>
-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch