[Intel-gfx] [PATCH 26/53] drm/i915/bdw: New logical ring submission mechanism

[Mateo Lozano, Oscar]

> -----Original Message-----
> From: Chris Wilson [mailto:chris at chris-wilson.co.uk]
> Sent: Monday, June 23, 2014 2:14 PM
> To: Mateo Lozano, Oscar
> Cc: Volkin, Bradley D; intel-gfx at lists.freedesktop.org
> Subject: Re: [Intel-gfx] [PATCH 26/53] drm/i915/bdw: New logical ring
> submission mechanism
> 
> On Mon, Jun 23, 2014 at 01:09:37PM +0000, Mateo Lozano, Oscar wrote:
> > So far, yes, but that´s only because I artificially made intel_lrc.c self-
> contained, as Daniel requested. What if we need to execute commands from
> somewhere else, like in intel_gen7_queue_flip()?
> >
> > And this takes me to another discussion: this logical ring vs legacy ring split
> is probably a good idea (time will tell), but we should provide a way of
> sending commands for execution without knowing if Execlists are enabled or
> not. In the early series that was easy because we reused the ring_begin,
> ring_emit & ring_advance functions, but this is not the case anymore. And
> without this, sooner or later somebody will break legacy or execlists (this
> already happened last week, when somebody here was implementing native
> sync without knowing about Execlists).
> >
> > So, the questions is: how do you feel about a dev_priv.gt vfunc that takes a
> context, a ring, an array of DWORDS and a BB length and does the
> intel_(logical)_ring_begin/emit/advance based on i915.enable_execlists?
> 
> I'm still baffled by the design. intel_ring_begin() and friends should be able to
> find their context (logical or legacy) from the ring and dtrt.
> -Chris

Sorry, Chris, I obviously don´t have the same experience with 915 you have: how do you propose to extract the right context from the ring?