This series does the same thing as my earlier series in that it adds a sync
object wait interface complete with WAIT_FOR_SUBMIT flag.  While the uapi
remains unchanged, the guts look a bit different.  Instead of adding a
callback mechanism to drm_syncobj that fired whenever replace_fence was
called, it's now using proxy fences.  The drm_syncobj_fence_get still
returns NULL whenever the sync object is in an unsubmitted state but there
is a new drm_syncobj_fence_proxy_get which returns either the real fence or
a proxy fence that will be triggered the next time replace_fence is called
with a non-NULL replacement.  This does make both drm_syncobj_fence_get and
drm_syncobj_replace_fence a tiny bit more expensive, but it lets us do it
all without locking.

This series can be found as a branch here:

found on patchwork here:

Patches to the Intel Vulkan driver to implement VK_KHR_external_fence on
top of this kernel interface can be found here:

Cc: Dave Airlie <>
Cc: Chris Wilson <>
Cc: Christian König <>

Chris Wilson (2):
  dma-buf/dma-fence: Signal all callbacks from dma_fence_release()
  dma-buf/dma-fence: Add a mechanism for proxy fences

Dave Airlie (1):
  drm/syncobj: add sync obj wait interface. (v8)

Jason Ekstrand (6):
  drm/syncobj: Rename fence_get to find_fence
  drm/syncobj: Add a race-free drm_syncobj_fence_get helper
  i915: Add support for drm syncobjs
  dma-buf/dma-fence: Allow wait_any_timeout without default_wait (v2)
  drm/syncobj: Add a reset ioctl
  drm/syncobj: Allow wait for submit and signal behavior (v4)

 drivers/dma-buf/Makefile                   |   4 +-
 drivers/dma-buf/dma-fence-proxy.c          | 186 +++++++++++++++++++
 drivers/dma-buf/dma-fence.c                |  34 ++--
 drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c     |   2 +-
 drivers/gpu/drm/drm_internal.h             |   4 +
 drivers/gpu/drm/drm_ioctl.c                |   4 +
 drivers/gpu/drm/drm_syncobj.c              | 275 +++++++++++++++++++++++++++--
 drivers/gpu/drm/i915/i915_drv.c            |   3 +-
 drivers/gpu/drm/i915/i915_gem_execbuffer.c | 146 ++++++++++++++-
 include/drm/drm_syncobj.h                  |  15 +-
 include/linux/dma-fence-proxy.h            |  25 +++
 include/uapi/drm/drm.h                     |  19 ++
 include/uapi/drm/i915_drm.h                |  30 +++-
 13 files changed, 710 insertions(+), 37 deletions(-)
 create mode 100644 drivers/dma-buf/dma-fence-proxy.c
 create mode 100644 include/linux/dma-fence-proxy.h


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