We don't want to create a fence for every command submission. It's only necessary when userspace provides a waitable token for submission. This could be:
1) bo_handles, to be used with VIRTGPU_WAIT 2) out_fence_fd, to be used with dma_fence apis 3) a ring_idx provided with VIRTGPU_CONTEXT_PARAM_POLL_RINGS_MASK + DRM event API 4) syncobjs in the future The use case for just submitting a command to the host, and expecting no response. For example, gfxstream has GFXSTREAM_CONTEXT_PING that just wakes up the host side worker threads. There's also CROSS_DOMAIN_CMD_SEND which just sends data to the Wayland server. This prevents the need to signal the automatically created virtio_gpu_fence. Signed-off-by: Gurchetan Singh <[email protected]> --- drivers/gpu/drm/virtio/virtgpu_submit.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/virtio/virtgpu_submit.c b/drivers/gpu/drm/virtio/virtgpu_submit.c index cf3c04b16a7a..add106c06ab2 100644 --- a/drivers/gpu/drm/virtio/virtgpu_submit.c +++ b/drivers/gpu/drm/virtio/virtgpu_submit.c @@ -168,9 +168,13 @@ static int virtio_gpu_init_submit(struct virtio_gpu_submit *submit, memset(submit, 0, sizeof(*submit)); - out_fence = virtio_gpu_fence_alloc(vgdev, fence_ctx, ring_idx); - if (!out_fence) - return -ENOMEM; + if ((exbuf->flags & VIRTGPU_EXECBUF_FENCE_FD_OUT) || + ((exbuf->flags & VIRTGPU_EXECBUF_RING_IDX) && + (vfpriv->ring_idx_mask & BIT_ULL(ring_idx))) || + exbuf->num_bo_handles) + out_fence = virtio_gpu_fence_alloc(vgdev, fence_ctx, ring_idx); + else + out_fence = NULL; err = virtio_gpu_fence_event_create(dev, file, out_fence, ring_idx); if (err) { -- 2.34.1
