On 6/13/23 20:43, Gurchetan Singh wrote: > 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) {
Looks okay, code indentation may be improved a tad to make it more eye-friendly: + 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; Checkpatch will complain about this variant, but the complaint can be ignored in this case. -- Best regards, Dmitry
