[Mesa-dev] [PATCH 3/3] anv: Use DRM sync objects for external semaphores when available

[Chris Wilson]

Quoting Jason Ekstrand (2017-07-05 18:21:08)
>  static void
>  anv_cmd_buffer_process_relocs(struct anv_cmd_buffer *cmd_buffer,
>                                struct anv_reloc_list *list)
> @@ -1450,6 +1484,14 @@ anv_cmd_buffer_execbuf(struct anv_device *device,
>           impl->fd = -1;
>           break;
>  
> +      case ANV_SEMAPHORE_TYPE_DRM_SYNCOBJ:
> +         result = anv_execbuf_add_syncobj(&execbuf, impl->syncobj,
> +                                          I915_EXEC_FENCE_WAIT,
> +                                          &device->alloc);

A wait on an uninitialized fence is invalid (it's a user error in the Vk
spec, right?). Similarly, I understood the spec to imply that once a
fence was used for waiting, it was consumed and invalid until it was
reinitialized via a signal operation later. Do you want to tell the
kernel to clear/reset the fence back to uninitialized after a wait?
(i.e. something like FENCE_WAIT | FENCE_UNSIGNAL)
-Chris