From ceae14bd4cc4333b9a3b0b6b9457bb16e7ca410a Mon Sep 17 00:00:00 2001
From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Wed, 3 May 2017 10:39:20 +0100
Subject: [PATCH] drm/i915: Lift timeline ordering to await_dma_fence
Git-commit: ceae14bd4cc4333b9a3b0b6b9457bb16e7ca410a
Patch-mainline: v4.13-rc1
References: FATE#322643 bsc#1055900
Currently we filter out repeated use of the same timeline in the low
level i915_gem_request_await_request(), after having added the
dependency on the old request. However, we can lift this to
i915_gem_request_await_dma_fence() (before the dependency is added)
using the observation that requests along the same timeline are
explicitly ordered via i915_add_request (along with the dependencies).
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170503093924.5320-3-chris@chris-wilson.co.uk
Acked-by: Takashi Iwai <tiwai@suse.de>
---
drivers/gpu/drm/i915/i915_gem_request.c | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)
--- a/drivers/gpu/drm/i915/i915_gem_request.c
+++ b/drivers/gpu/drm/i915/i915_gem_request.c
@@ -687,6 +687,7 @@ i915_gem_request_await_request(struct dr
int ret;
GEM_BUG_ON(to == from);
+ GEM_BUG_ON(to->timeline == from->timeline);
if (i915_gem_request_completed(from))
return 0;
@@ -699,9 +700,6 @@ i915_gem_request_await_request(struct dr
return ret;
}
- if (to->timeline == from->timeline)
- return 0;
-
if (to->engine == from->engine) {
ret = i915_sw_fence_await_sw_fence_gfp(&to->submit,
&from->submit,
@@ -767,6 +765,14 @@ i915_gem_request_await_dma_fence(struct
if (test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags))
continue;
+ /*
+ * Requests on the same timeline are explicitly ordered, along
+ * with their dependencies, by i915_add_request() which ensures
+ * that requests are submitted in-order through each ring.
+ */
+ if (fence->context == req->fence.context)
+ continue;
+
if (dma_fence_is_i915(fence))
ret = i915_gem_request_await_request(req,
to_request(fence));