[PATCH v2] drm/doc: document front-buffer rendering

[Pekka Paalanen]

On Mon, 14 Apr 2025 08:56:56 +0000
Simon Ser <contact at emersion.fr> wrote:

> Explain how to perform front-buffer rendering.
> 
> v2: apply Pekka's rewrite
> 
> Signed-off-by: Simon Ser <contact at emersion.fr>
> Cc: Pekka Paalanen <pekka.paalanen at collabora.com>
> Cc: Simona Vetter <simona.vetter at ffwll.ch>
> ---
>  drivers/gpu/drm/drm_blend.c | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/drivers/gpu/drm/drm_blend.c b/drivers/gpu/drm/drm_blend.c
> index 6e74de833466..4e83f372ea51 100644
> --- a/drivers/gpu/drm/drm_blend.c
> +++ b/drivers/gpu/drm/drm_blend.c
> @@ -75,6 +75,12 @@
>   * 	the currently visible vertical area of the &drm_crtc.
>   * FB_ID:
>   * 	Mode object ID of the &drm_framebuffer this plane should scan out.
> + *
> + *	When a KMS client is perfoming front-buffer rendering, it should set
> + *	FB_ID to the same front-buffer FB on each atomic commit. This implies
> + *	to the driver that it needs to re-read the same FB again. Otherwise
> + *	drivers which do not employ continuously repeated scanout cycles might
> + *	not update the screen.
>   * CRTC_ID:
>   * 	Mode object ID of the &drm_crtc this plane should be connected to.
>   *

Looking good, but given the new wording is 100% mine, not sure I can
give reviewed-by?

Co-authored-by maybe?


Thanks,
pq
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