Re: [PATCH] drm/mediatek: crtc: Make config-updating atomic

[Chun-Kuang Hu]

Applied to mediatek-drm-next [1].

[1] https://git.kernel.org/pub/scm/linux/kernel/git/chunkuang.hu/linux.git/log/?h=mediatek-drm-next

Regards,
Chun-Kuang.

Chun-Kuang Hu <chunkuang.hu@xxxxxxxxxx> 於 2021年3月13日 週六 下午5:43寫道：
>
> While updating config, the irq would occur and get the partial
> config, so use variable config_updating to make updating atomic.
>
> Signed-off-by: Chun-Kuang Hu <chunkuang.hu@xxxxxxxxxx>
> ---
>  drivers/gpu/drm/mediatek/mtk_drm_crtc.c | 19 ++++++++++++-------
>  1 file changed, 12 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
> index 8b0de90156c6..870f66210848 100644
> --- a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
> +++ b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
> @@ -61,6 +61,7 @@ struct mtk_drm_crtc {
>
>         /* lock for display hardware access */
>         struct mutex                    hw_lock;
> +       bool                            config_updating;
>  };
>
>  struct mtk_crtc_state {
> @@ -97,7 +98,7 @@ static void mtk_drm_crtc_finish_page_flip(struct mtk_drm_crtc *mtk_crtc)
>  static void mtk_drm_finish_page_flip(struct mtk_drm_crtc *mtk_crtc)
>  {
>         drm_crtc_handle_vblank(&mtk_crtc->base);
> -       if (mtk_crtc->pending_needs_vblank) {
> +       if (!mtk_crtc->config_updating && mtk_crtc->pending_needs_vblank) {
>                 mtk_drm_crtc_finish_page_flip(mtk_crtc);
>                 mtk_crtc->pending_needs_vblank = false;
>         }
> @@ -425,7 +426,8 @@ static void mtk_crtc_ddp_config(struct drm_crtc *crtc,
>         }
>  }
>
> -static void mtk_drm_crtc_hw_config(struct mtk_drm_crtc *mtk_crtc)
> +static void mtk_drm_crtc_update_config(struct mtk_drm_crtc *mtk_crtc,
> +                                      bool needs_vblank)
>  {
>  #if IS_REACHABLE(CONFIG_MTK_CMDQ)
>         struct cmdq_pkt *cmdq_handle;
> @@ -436,6 +438,10 @@ static void mtk_drm_crtc_hw_config(struct mtk_drm_crtc *mtk_crtc)
>         int i;
>
>         mutex_lock(&mtk_crtc->hw_lock);
> +       mtk_crtc->config_updating = true;
> +       if (needs_vblank)
> +               mtk_crtc->pending_needs_vblank = true;
> +
>         for (i = 0; i < mtk_crtc->layer_nr; i++) {
>                 struct drm_plane *plane = &mtk_crtc->planes[i];
>                 struct mtk_plane_state *plane_state;
> @@ -472,6 +478,7 @@ static void mtk_drm_crtc_hw_config(struct mtk_drm_crtc *mtk_crtc)
>                 cmdq_pkt_flush_async(cmdq_handle, ddp_cmdq_cb, cmdq_handle);
>         }
>  #endif
> +       mtk_crtc->config_updating = false;
>         mutex_unlock(&mtk_crtc->hw_lock);
>  }
>
> @@ -532,7 +539,7 @@ void mtk_drm_crtc_async_update(struct drm_crtc *crtc, struct drm_plane *plane,
>                 return;
>
>         plane_helper_funcs->atomic_update(plane, new_state);
> -       mtk_drm_crtc_hw_config(mtk_crtc);
> +       mtk_drm_crtc_update_config(mtk_crtc, false);
>  }
>
>  static void mtk_drm_crtc_atomic_enable(struct drm_crtc *crtc,
> @@ -582,7 +589,7 @@ static void mtk_drm_crtc_atomic_disable(struct drm_crtc *crtc,
>         }
>         mtk_crtc->pending_planes = true;
>
> -       mtk_drm_crtc_hw_config(mtk_crtc);
> +       mtk_drm_crtc_update_config(mtk_crtc, false);
>         /* Wait for planes to be disabled */
>         drm_crtc_wait_one_vblank(crtc);
>
> @@ -618,14 +625,12 @@ static void mtk_drm_crtc_atomic_flush(struct drm_crtc *crtc,
>         struct mtk_drm_crtc *mtk_crtc = to_mtk_crtc(crtc);
>         int i;
>
> -       if (mtk_crtc->event)
> -               mtk_crtc->pending_needs_vblank = true;
>         if (crtc->state->color_mgmt_changed)
>                 for (i = 0; i < mtk_crtc->ddp_comp_nr; i++) {
>                         mtk_ddp_gamma_set(mtk_crtc->ddp_comp[i], crtc->state);
>                         mtk_ddp_ctm_set(mtk_crtc->ddp_comp[i], crtc->state);
>                 }
> -       mtk_drm_crtc_hw_config(mtk_crtc);
> +       mtk_drm_crtc_update_config(mtk_crtc, !!mtk_crtc->event);
>  }
>
>  static const struct drm_crtc_funcs mtk_crtc_funcs = {
> --
> 2.17.1
>