Re: [PATCH v6 3/6] drm/mediatek: Detect CMDQ execution timeout

Re: [PATCH v6 3/6] drm/mediatek: Detect CMDQ execution timeout

[Fei Shao]

On Thu, Oct 28, 2021 at 6:19 PM jason-jh.lin <jason-jh.lin@mediatek.com> wrote:
>
> From: Chun-Kuang Hu <chunkuang.hu@kernel.org>
>
> CMDQ is used to update display register in vblank period, so
> it should be execute in next 2 vblank. One vblank interrupt
> before send message (occasionally) and one vblank interrupt
> after cmdq done. If it fail to execute in next 3 vblank,
> tiemout happen.
>
> Signed-off-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>
> Signed-off-by: jason-jh.lin <jason-jh.lin@mediatek.com>
Reviewed-by: Fei Shao <fshao@chromium.org>



> ---
>  drivers/gpu/drm/mediatek/mtk_drm_crtc.c | 20 ++++++++++++++++++--
>  1 file changed, 18 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
> index e23e3224ac67..a368cbc18923 100644
> --- a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
> +++ b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
> @@ -54,6 +54,7 @@ struct mtk_drm_crtc {
>  #if IS_REACHABLE(CONFIG_MTK_CMDQ)
>         struct cmdq_client              cmdq_client;
>         u32                             cmdq_event;
> +       u32                             cmdq_vblank_cnt;
>  #endif
>
>         struct device                   *mmsys_dev;
> @@ -227,7 +228,10 @@ struct mtk_ddp_comp *mtk_drm_ddp_comp_for_plane(struct drm_crtc *crtc,
>  static void ddp_cmdq_cb(struct mbox_client *cl, void *mssg)
>  {
>         struct cmdq_cb_data *data = mssg;
> +       struct cmdq_client *cmdq_cl = container_of(cl, struct cmdq_client, client);
> +       struct mtk_drm_crtc *mtk_crtc = container_of(cmdq_cl, struct mtk_drm_crtc, cmdq_client);
>
> +       mtk_crtc->cmdq_vblank_cnt = 0;
>         cmdq_pkt_destroy(data->pkt);
>  }
>  #endif
> @@ -483,6 +487,15 @@ static void mtk_drm_crtc_update_config(struct mtk_drm_crtc *mtk_crtc,
>                                            cmdq_handle->pa_base,
>                                            cmdq_handle->cmd_buf_size,
>                                            DMA_TO_DEVICE);
> +               /*
> +                * CMDQ command should execute in next 3 vblank.
> +                * One vblank interrupt before send message (occasionally)
> +                * and one vblank interrupt after cmdq done,
> +                * so it's timeout after 3 vblank interrupt.
> +                * If it fail to execute in next 3 vblank, timeout happen.
> +                */
> +               mtk_crtc->cmdq_vblank_cnt = 3;
> +
>                 mbox_send_message(mtk_crtc->cmdq_client.chan, cmdq_handle);
>                 mbox_client_txdone(mtk_crtc->cmdq_client.chan, 0);
>         }
> @@ -499,11 +512,14 @@ static void mtk_crtc_ddp_irq(void *data)
>
>  #if IS_REACHABLE(CONFIG_MTK_CMDQ)
>         if (!priv->data->shadow_register && !mtk_crtc->cmdq_client.chan)
> +               mtk_crtc_ddp_config(crtc, NULL);
> +       else if (--mtk_crtc->cmdq_vblank_cnt == 0)
> +               DRM_ERROR("mtk_crtc %d CMDQ execute command timeout!\n",
> +                         drm_crtc_index(&mtk_crtc->base));
>  #else
>         if (!priv->data->shadow_register)
> -#endif
>                 mtk_crtc_ddp_config(crtc, NULL);
> -
> +#endif
>         mtk_drm_finish_page_flip(mtk_crtc);
>  }
>
> --
> 2.18.0
>

Re: [PATCH v6 0/5] CMDQ refinement of Mediatek DRM driver

[Chun-Kuang Hu]

Hi, Jason:

For this series except [v6,3/6] drm/mediatek: Detect CMDQ execution
timeout (I pick v5), applied to mediatek-drm-next [1], thanks.

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

Regards,
Chun-Kuang.

jason-jh.lin <jason-jh.lin@mediatek.com> 於 2021年10月28日 週四 下午6:19寫道：
>
> Change in v6:
> 1. Drop the redundant checking of cmdq_vblank_cnt .
> 2. fix the indent.
>
> Change in v5:
> 1. Move mbox_free_channel to a independent patch.
>
> Change in v4:
> 1. Add cmdq_vblank_cnt initial value to 3.
> 2. Move mtk_drm_cmdq_pkt_create to the same define scope with
>    mtk_drm_cmdq_pkt_destroy.
>
> Change in v3:
> 1. Revert "drm/mediatek: clear pending flag when cmdq packet is done"
>    and add it after the CMDQ refinement patches.
> 2. Change the remove of struct cmdq_client to remove the pointer of
>    struct cmdq_client.
> 3. Fix pkt buf alloc once but free many times.
>
> Changes in v2:
> 1. Define mtk_drm_cmdq_pkt_create() and mtk_drm_cmdq_pkt_destroy()
>    when CONFIG_MTK_CMDQ is reachable.
>
> Chun-Kuang Hu (4):
>   drm/mediatek: Use mailbox rx_callback instead of cmdq_task_cb
>   drm/mediatek: Remove the pointer of struct cmdq_client
>   drm/mediatek: Detect CMDQ execution timeout
>   drm/mediatek: Add cmdq_handle in mtk_crtc
>
> Yongqiang Niu (1):
>   drm/mediatek: Clear pending flag when cmdq packet is done
>
> jason-jh.lin (1):
>   drm/mediatek: Add mbox_free_channel in mtk_drm_crtc_destroy
>
>  drivers/gpu/drm/mediatek/mtk_drm_crtc.c | 175 ++++++++++++++++++++----
>  1 file changed, 151 insertions(+), 24 deletions(-)
>
> --
> 2.18.0
>