On Mon, Jun 30, 2014 at 09:51:11AM -0700, Rodrigo Vivi wrote: > ring index calculation table was out of date after other rings were added, > although the formula is flexible and scale when adding new rings. > > So this patch just update the comments and add a brief explanation > why to use sync_seqno[ring index]. > > Signed-off-by: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx> > --- > drivers/gpu/drm/i915/i915_gem.c | 2 ++ > drivers/gpu/drm/i915/intel_ringbuffer.h | 8 +++++--- > 2 files changed, 7 insertions(+), 3 deletions(-) > > diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c > index f6d1238..e85c85c 100644 > --- a/drivers/gpu/drm/i915/i915_gem.c > +++ b/drivers/gpu/drm/i915/i915_gem.c > @@ -2842,6 +2842,8 @@ i915_gem_object_sync(struct drm_i915_gem_object *obj, > idx = intel_ring_sync_index(from, to); > > seqno = obj->last_read_seqno; > + /* Optimization: Avoid semaphore sync when we are sure we already > + * waited for an object with higher seqno */ > if (seqno <= from->semaphore.sync_seqno[idx]) > return 0; > > diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h > index e72017b..2e8b516 100644 > --- a/drivers/gpu/drm/i915/intel_ringbuffer.h > +++ b/drivers/gpu/drm/i915/intel_ringbuffer.h > @@ -238,9 +238,11 @@ intel_ring_sync_index(struct intel_engine_cs *ring, > int idx; > > /* > - * cs -> 0 = vcs, 1 = bcs > - * vcs -> 0 = bcs, 1 = cs, > - * bcs -> 0 = cs, 1 = vcs. > + * rcs -> 0 = vcs, 1 = bcs, 2 = vecs, 3 = vcs2; > + * vcs -> 0 = bcs, 1 = vecs, 2 = vcs2, 3 = rcs; > + * bcs -> 0 = vecs, 1 = vcs2. 2 = rcs, 3 = vcs; > + * vecs -> 0 = vcs2, 1 = rcs, 2 = vcs, 3 = bcs; > + * vcs2 -> 0 = rcs, 1 = vcs, 2 = bcs, 3 = vecs; > */ I'd be a favor of dropping this table, and instead explaining the goal of the math (to save the dword) > > idx = (other - ring) - 1; I'm guessing this hunk is from your private branch? In any event, the topmost comment is a nice addition: Reviewed-by: Ben Widawsky <ben@xxxxxxxxxxxx> -- Ben Widawsky, Intel Open Source Technology Center _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx
