From f8bd0069bbbc4c72452d29a4a8647bfb8c1ca2c3 Mon Sep 17 00:00:00 2001
From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Mon, 3 Feb 2020 09:41:47 +0000
Subject: drm/i915: Hold reference to previous active fence as we queue
Git-commit: 30ca04e16cbeea7401dabc51e53b92975144e436
Patch-mainline: v5.7-rc1
References: jsc#SLE-12680, jsc#SLE-12880, jsc#SLE-12882, jsc#SLE-12883, jsc#SLE-13496, jsc#SLE-15322
Take a reference to the previous exclusive fence on the i915_active, as
we wish to add an await to it in the caller (and so must prevent it from
being freed until we have completed that task).
Fixes: e3793468b466 ("drm/i915: Use the async worker to avoid reclaim tainting the ggtt->mutex")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Matthew Auld <matthew.auld@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200203094152.4150550-1-chris@chris-wilson.co.uk
Signed-off-by: Patrik Jakobsson <pjakobsson@suse.de>
---
drivers/gpu/drm/i915/i915_active.c | 6 +++++-
drivers/gpu/drm/i915/i915_vma.c | 4 +++-
2 files changed, 8 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_active.c b/drivers/gpu/drm/i915/i915_active.c
index da58e5d084f4..9ccb931a733e 100644
--- a/drivers/gpu/drm/i915/i915_active.c
+++ b/drivers/gpu/drm/i915/i915_active.c
@@ -398,9 +398,13 @@ i915_active_set_exclusive(struct i915_active *ref, struct dma_fence *f)
/* We expect the caller to manage the exclusive timeline ordering */
GEM_BUG_ON(i915_active_is_idle(ref));
+ rcu_read_lock();
prev = __i915_active_fence_set(&ref->excl, f);
- if (!prev)
+ if (prev)
+ prev = dma_fence_get_rcu(prev);
+ else
atomic_inc(&ref->count);
+ rcu_read_unlock();
return prev;
}
diff --git a/drivers/gpu/drm/i915/i915_vma.c b/drivers/gpu/drm/i915/i915_vma.c
index e801e28de470..74dc3ba59ce5 100644
--- a/drivers/gpu/drm/i915/i915_vma.c
+++ b/drivers/gpu/drm/i915/i915_vma.c
@@ -422,10 +422,12 @@ int i915_vma_bind(struct i915_vma *vma,
* execution and not content or object's backing store lifetime.
*/
prev = i915_active_set_exclusive(&vma->active, &work->base.dma);
- if (prev)
+ if (prev) {
__i915_sw_fence_await_dma_fence(&work->base.chain,
prev,
&work->cb);
+ dma_fence_put(prev);
+ }
work->base.dma.error = 0; /* enable the queue_work() */
--
2.28.0