Quoting Laurent Pinchart (2022-02-21 17:13:40)
> On Gen3 hardware enabling a VSP plane doesn't change any register that
> requires DRES to take effect. Avoid a group restart in that case.
This also makes it clear that the need_restart is due to the change
occuring in the VSP1 sink, so I think this is cleaner all round.
Reviewed-by: Kieran Bingham <kieran.bingham+renesas@xxxxxxxxxxxxxxxx>
>
> Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@xxxxxxxxxxxxxxxx>
> ---
> drivers/gpu/drm/rcar-du/rcar_du_plane.c | 6 ++++++
> drivers/gpu/drm/rcar-du/rcar_du_vsp.c | 9 ---------
> 2 files changed, 6 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/gpu/drm/rcar-du/rcar_du_plane.c b/drivers/gpu/drm/rcar-du/rcar_du_plane.c
> index 9b058d6cb032..22aeeb1cc1fb 100644
> --- a/drivers/gpu/drm/rcar-du/rcar_du_plane.c
> +++ b/drivers/gpu/drm/rcar-du/rcar_du_plane.c
> @@ -560,6 +560,12 @@ void __rcar_du_plane_setup(struct rcar_du_group *rgrp,
> if (rcdu->vspd1_sink != vspd1_sink) {
> rcdu->vspd1_sink = vspd1_sink;
> rcar_du_set_dpad0_vsp1_routing(rcdu);
> +
> + /*
> + * Changes to the VSP1 sink take effect on DRES and thus
> + * need a restart of the group.
> + */
> + rgrp->need_restart = true;
> }
> }
> }
> diff --git a/drivers/gpu/drm/rcar-du/rcar_du_vsp.c b/drivers/gpu/drm/rcar-du/rcar_du_vsp.c
> index b7fc5b069cbc..32530d698e75 100644
> --- a/drivers/gpu/drm/rcar-du/rcar_du_vsp.c
> +++ b/drivers/gpu/drm/rcar-du/rcar_du_vsp.c
> @@ -84,15 +84,6 @@ void rcar_du_vsp_enable(struct rcar_du_crtc *crtc)
>
> __rcar_du_plane_setup(crtc->group, &state);
>
> - /*
> - * Ensure that the plane source configuration takes effect by requesting
> - * a restart of the group. See rcar_du_plane_atomic_update() for a more
> - * detailed explanation.
> - *
> - * TODO: Check whether this is still needed on Gen3.
> - */
> - crtc->group->need_restart = true;
> -
> vsp1_du_setup_lif(crtc->vsp->vsp, crtc->vsp_pipe, &cfg);
> }
>
> --
> Regards,
>
> Laurent Pinchart
>
