# Re: \[PATCH\] Add virtio gpu driver.

- From: Daniel Stone \<hidden\>
- Date: 2015-03-24 22:50:33 
- List: linux-api
- Page: https://ratatoskr.run/linux-api/2015/03/4458572
- Thread: https://ratatoskr.run/linux-api/2015/03/4458206/t.md

```text
Hi,

On 24 March 2015 at 16:07, Gerd Hoffmann [ref] wrote:
> +static int virtio_gpu_crtc_page_flip(struct drm_crtc *crtc,
> +                                    struct drm_framebuffer *fb,
> +                                    struct drm_pending_vblank_event *event,
> +                                    uint32_t flags)
> +{
> +       return -EINVAL;
> +}

I'm not going to lie, I was really hoping the 5th (?) GPU option for
Qemu would support pageflipping. Daniel's comment about conversion to
atomic is relevant, but: do you have a mechanism which allows you to
post updates (e.g. 'start displaying this buffer now please') that
allows you to get events back when they have actually been displayed?

Cheers,
Daniel
```