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| author | Nicolai Hähnle <nicolai.haehnle@amd.com> | 2016-02-05 10:59:43 -0500 |
|---|---|---|
| committer | Alex Deucher <alexander.deucher@amd.com> | 2016-02-10 14:07:31 -0500 |
| commit | a8d81b36267366603771431747438d18f32ae2d5 (patch) | |
| tree | fb6460edb485890a55b6a101751812abcfb0b7c1 /drivers | |
| parent | ca19852884c8937eed89560f924f5a34cfcc22af (diff) | |
| download | linux-a8d81b36267366603771431747438d18f32ae2d5.tar.bz2 | |
drm/amdgpu: hold reference to fences in amdgpu_sa_bo_new (v2)
An arbitrary amount of time can pass between spin_unlock and
fence_wait_any_timeout, so we need to ensure that nobody frees the
fences from under us.
A stress test (rapidly starting and killing hundreds of glxgears
instances) ran into a deadlock in fence_wait_any_timeout after
about an hour, and this race condition appears to be a plausible
cause.
v2: agd: rebase on upstream
Signed-off-by: Nicolai Hähnle <nicolai.haehnle@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Cc: stable@vger.kernel.org
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/gpu/drm/amd/amdgpu/amdgpu_sa.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_sa.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_sa.c index 8b88edb0434b..ca72a2e487b9 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_sa.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_sa.c @@ -354,12 +354,15 @@ int amdgpu_sa_bo_new(struct amdgpu_sa_manager *sa_manager, for (i = 0, count = 0; i < AMDGPU_MAX_RINGS; ++i) if (fences[i]) - fences[count++] = fences[i]; + fences[count++] = fence_get(fences[i]); if (count) { spin_unlock(&sa_manager->wq.lock); t = fence_wait_any_timeout(fences, count, false, MAX_SCHEDULE_TIMEOUT); + for (i = 0; i < count; ++i) + fence_put(fences[i]); + r = (t > 0) ? 0 : t; spin_lock(&sa_manager->wq.lock); } else { |