[Intel-gfx] [RFC 2/5] drm/i915: Unify execlist and legacy request life-cycles

[Chris Wilson]

On Thu, Jul 09, 2015 at 11:57:41AM +0100, Nick Hoath wrote:
> There is a desire to simplify the i915 driver by reducing the number of
> different code paths introduced by the LRC / execlists support.  As the
> execlists request is now part of the gem request it is possible and
> desirable to unify the request life-cycles for execlist and legacy
> requests.
> 
> Added a context complete flag to a request which gets set during the
> context switch interrupt.
> 
> Added a function i915_gem_request_retireable().  A request is considered
> retireable if its seqno passed (i.e. the request has completed) and either
> it was never submitted to the ELSP or its context completed.  This ensures
> that context save is carried out before the last request for a context is
> considered retireable.  retire_requests_ring() now uses
> i915_gem_request_retireable() rather than request_complete() when deciding
> which requests to retire. Requests that were not waiting for a context
> switch interrupt (either as a result of being merged into a following
> request or by being a legacy request) will be considered retireable as
> soon as their seqno has passed.

Nak. Just keep the design as requests only retire when seqno passes.
 
> Removed the extra request reference held for the execlist request.
> 
> Removed intel_execlists_retire_requests() and all references to
> intel_engine_cs.execlist_retired_req_list.
> 
> Moved context unpinning into retire_requests_ring() for now.  Further work
> is pending for the context pinning - this patch should allow us to use the
> active list to track context and ring buffer objects later.
> 
> Changed gen8_cs_irq_handler() so that notify_ring() is called when
> contexts complete as well as when a user interrupt occurs so that
> notification happens when a request is complete and context save has
> finished.
> 
> v2: Rebase over the read-read optimisation changes

Any reason why you didn't review my patches to do this much more neatly?
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre