Re: [PATCH v4 3/5] drm/mediatek: Detect CMDQ execution timeout

Hi, Jason:

jason-jh.lin jason-jh.lin@mediatek.com 於 2021年10月26日 週二 下午1:29寫道：

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.

Reviewed-by: Chun-Kuang Hu chunkuang.hu@kernel.org

Signed-off-by: Chun-Kuang Hu chunkuang.hu@kernel.org Signed-off-by: jason-jh.lin jason-jh.lin@mediatek.com

---

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..dad1f85ee315 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 && --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