Re: [PATCH v4 2/2] drm/mediatek: add devlink to cmdq dev

[Chun-Kuang Hu]

Hi, Jason:

jason-jh.lin <jason-jh.lin@xxxxxxxxxxxx> 於 2021年12月2日 週四 下午2:41寫道：
>
> Add devlink to cmdq to make sure the order of suspend and resume
> is correct.
>

Reviewed-by: Chun-Kuang Hu <chunkuang.hu@xxxxxxxxxx>

> Signed-off-by: jason-jh.lin <jason-jh.lin@xxxxxxxxxxxx>
> ---
>  drivers/gpu/drm/mediatek/mtk_drm_crtc.c | 43 ++++++++++++++++++-------
>  1 file changed, 31 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
> index 0b4012335e7a..612d1d69c16c 100644
> --- a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
> +++ b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
> @@ -60,6 +60,7 @@ struct mtk_drm_crtc {
>  #endif
>
>         struct device                   *mmsys_dev;
> +       struct device                   *drm_dev;
>         struct mtk_mutex                *mutex;
>         unsigned int                    ddp_comp_nr;
>         struct mtk_ddp_comp             **ddp_comp;
> @@ -159,6 +160,7 @@ static void mtk_drm_crtc_destroy(struct drm_crtc *crtc)
>         mtk_drm_cmdq_pkt_destroy(&mtk_crtc->cmdq_handle);
>
>         if (mtk_crtc->cmdq_client.chan) {
> +               device_link_remove(mtk_crtc->drm_dev, mtk_crtc->cmdq_client.chan->mbox->dev);
>                 mbox_free_channel(mtk_crtc->cmdq_client.chan);
>                 mtk_crtc->cmdq_client.chan = NULL;
>         }
> @@ -902,6 +904,7 @@ int mtk_drm_crtc_create(struct drm_device *drm_dev,
>                 return -ENOMEM;
>
>         mtk_crtc->mmsys_dev = priv->mmsys_dev;
> +       mtk_crtc->drm_dev = priv->dev;
>         mtk_crtc->ddp_comp_nr = path_len;
>         mtk_crtc->ddp_comp = devm_kmalloc_array(dev, mtk_crtc->ddp_comp_nr,
>                                                 sizeof(*mtk_crtc->ddp_comp),
> @@ -969,6 +972,18 @@ int mtk_drm_crtc_create(struct drm_device *drm_dev,
>         }
>
>         if (mtk_crtc->cmdq_client.chan) {
> +               struct device_link *link;
> +
> +               /* add devlink to cmdq dev to make sure suspend/resume order is correct */
> +               link = device_link_add(priv->dev, mtk_crtc->cmdq_client.chan->mbox->dev,
> +                                      DL_FLAG_PM_RUNTIME | DL_FLAG_STATELESS);
> +               if (!link) {
> +                       dev_err(priv->dev, "Unable to link dev=%s\n",
> +                               dev_name(mtk_crtc->cmdq_client.chan->mbox->dev));
> +                       ret = -ENODEV;
> +                       goto cmdq_err;
> +               }
> +
>                 ret = of_property_read_u32_index(priv->mutex_node,
>                                                  "mediatek,gce-events",
>                                                  i,
> @@ -976,22 +991,26 @@ int mtk_drm_crtc_create(struct drm_device *drm_dev,
>                 if (ret) {
>                         dev_dbg(dev, "mtk_crtc %d failed to get mediatek,gce-events property\n",
>                                 drm_crtc_index(&mtk_crtc->base));
> -                       mbox_free_channel(mtk_crtc->cmdq_client.chan);
> -                       mtk_crtc->cmdq_client.chan = NULL;
> -               } else {
> -                       ret = mtk_drm_cmdq_pkt_create(&mtk_crtc->cmdq_client,
> -                                                     &mtk_crtc->cmdq_handle,
> -                                                     PAGE_SIZE);
> -                       if (ret) {
> -                               dev_dbg(dev, "mtk_crtc %d failed to create cmdq packet\n",
> -                                       drm_crtc_index(&mtk_crtc->base));
> -                               mbox_free_channel(mtk_crtc->cmdq_client.chan);
> -                               mtk_crtc->cmdq_client.chan = NULL;
> -                       }
> +                       goto cmdq_err;
> +               }
> +
> +               ret = mtk_drm_cmdq_pkt_create(&mtk_crtc->cmdq_client,
> +                                             &mtk_crtc->cmdq_handle,
> +                                             PAGE_SIZE);
> +               if (ret) {
> +                       dev_dbg(dev, "mtk_crtc %d failed to create cmdq packet\n",
> +                               drm_crtc_index(&mtk_crtc->base));
> +                       goto cmdq_err;
>                 }
>
>                 /* for sending blocking cmd in crtc disable */
>                 init_waitqueue_head(&mtk_crtc->cb_blocking_queue);
> +
> +cmdq_err:
> +               if (ret) {
> +                       mbox_free_channel(mtk_crtc->cmdq_client.chan);
> +                       mtk_crtc->cmdq_client.chan = NULL;
> +               }
>         }
>  #endif
>         return 0;
> --
> 2.18.0
>