From dba5a7f301d2eec0ed1b2fbe3156960615b996d5 Mon Sep 17 00:00:00 2001
From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Wed, 15 May 2019 14:00:48 +0100
Subject: [PATCH] drm/i915: Mark semaphores as complete on unsubmit out if
payload was started
Avoid charging us for the presumed busywait if the request was preempted
after successfully using semaphores to reduce inter-engine latency.
v2: Bump the priority to reflect the lack of semaphores now required.
References: ca6e56f654e7 ("drm/i915: Disable semaphore busywaits on saturated systems")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190515130052.4475-1-chris@chris-wilson.co.uk
---
drivers/gpu/drm/i915/i915_request.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c
index bed213148cbb5..11670774cd257 100644
--- a/drivers/gpu/drm/i915/i915_request.c
+++ b/drivers/gpu/drm/i915/i915_request.c
@@ -509,6 +509,12 @@ void __i915_request_unsubmit(struct i915_request *request)
/* Transfer back from the global per-engine timeline to per-context */
move_to_timeline(request, request->timeline);
+ /* We've already spun, don't charge on resubmitting. */
+ if (request->sched.semaphores && i915_request_started(request)) {
+ request->sched.attr.priority |= I915_PRIORITY_NOSEMAPHORE;
+ request->sched.semaphores = 0;
+ }
+
/*
* We don't need to wake_up any waiters on request->execute, they
* will get woken by any other event or us re-adding this request
--
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