freedreno: Allow TC async fences to have an fd

We don't need to have this restriction, we just need to fence_flush()
before trying to access the fd.  This path is exercised in CL CTS
gl-interop test if cl_gl_sharing is exposed.

Signed-off-by: Rob Clark <rob.clark@oss.qualcomm.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/37696>

src/gallium/drivers/freedreno/freedreno_context.c

@@ -46,12 +46,6 @@ fd_context_flush(struct pipe_context *pctx, struct pipe_fence_handle **fencep,
     * one created earlier
     */
    if ((flags & TC_FLUSH_ASYNC) && fencep) {
-      /* We don't currently expect async+flush in the fence-fd
-       * case.. for that to work properly we'd need TC to tell
-       * us in the create_fence callback that it needs an fd.
-       */
-      assert(!(flags & PIPE_FLUSH_FENCE_FD));
-
       fd_pipe_fence_set_batch(*fencep, batch);
       fd_pipe_fence_ref(&batch->fence, *fencep);
 

src/gallium/drivers/freedreno/freedreno_fence.c

@@ -316,13 +316,13 @@ fd_pipe_fence_get_fd(struct pipe_screen *pscreen, struct pipe_fence_handle *fenc
    /* We don't expect deferred flush to be combined with fence-fd: */
    assert(!fence->last_fence);
 
-   assert(fence->use_fence_fd);
 
    /* NOTE: in the deferred fence case, the pctx we want is the threaded-ctx
     * but if TC is not used, this will be null.  Which is fine, we won't call
     * threaded_context_flush() in that case
     */
    fence_flush(&fence->ctx->tc->base, fence, OS_TIMEOUT_INFINITE);
+   assert(fence->use_fence_fd);
    assert(fence->fence);
    return os_dupfd_cloexec(fence->fence->fence_fd);
 }