From 23a35038b14b1b3a892fd6e0f70ef6a88f32f1b9 Mon Sep 17 00:00:00 2001 From: Rodrigo Vivi Date: Mon, 30 Jun 2014 09:51:11 -0700 Subject: [PATCH] drm/i915: Updating comments. ring index calculation table was out of date after other rings were added, although the formula is flexible and scale when adding new rings.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 Reviewed-by: Ben Widawsky Signed-off-by: Daniel Vetter --- 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 f6d123828926f..e85c85c0333e3 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 e72017bdcd7f8..2e8b51645bcbe 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; */ idx = (other - ring) - 1; -- 2.39.5