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

[Tvrtko Ursulin]

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>

Regards,

Tvrtko