On Thu, Oct 28, 2021 at 6:19 PM jason-jh.lin <jason-jh.lin@xxxxxxxxxxxx> wrote:
>
> From: Chun-Kuang Hu <chunkuang.hu@xxxxxxxxxx>
>
> 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@xxxxxxxxxx>
> Signed-off-by: jason-jh.lin <jason-jh.lin@xxxxxxxxxxxx>
Reviewed-by: Fei Shao <fshao@xxxxxxxxxxxx>
> ---
> 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
>
