[Intel-gfx] [RFC 2/2] drm/i915: Engine capabilities uAPI

[Chris Wilson]

Quoting Tvrtko Ursulin (2017-06-21 10:13:57)
> From: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> 
> This is a lighter-weight alternative to the previously posted
> RFC titled "drm/i915: Engine discovery uAPI" which still allows
> some engine configuration probing without depending on PCI ids.
> 
> Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> Cc: Ben Widawsky <ben at bwidawsk.net>
> Cc: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Daniel Vetter <daniel.vetter at intel.com>
> Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
> Cc: Jon Bloomfield <jon.bloomfield at intel.com>
> Cc: "Rogozhkin, Dmitry V" <dmitry.v.rogozhkin at intel.com>
> Cc: Oscar Mateo <oscar.mateo at intel.com>
> Cc: "Gong, Zhipeng" <zhipeng.gong at intel.com>
> Cc: intel-vaapi-media at lists.01.org
> --
> Floating as an alternative to the heavier engine discovery API
> sent previously which did not manage to gain much interest from
> userspace clients.
> 
> With this one enumeration and feature discovery would be done by
> sending null batches to all engine instances. Downside is less
> extensibility if we are using a fixed and smaller number of eb
> flags.

But we lose out on features? Just after you convinced me that features
was what we wanted! :-p
-Chris