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 expected
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 <gurchetansingh@xxxxxxxxxxxx>
Reviewed-by: <dmitry.osipenko@xxxxxxxxxxxxx>
---
v2: Fix indent (Dmitry)
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..8c7e15c31164 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) {
--
2.41.0.162.gfafddb0af9-goog
