Re: [PATCH v1] drm/mediatek: move page flip handle into cmdq cb

Hi, Yongqiang:

Yongqiang Niu yongqiang.niu@mediatek.com 於 2021年2月19日 週五 下午5:54寫道：

move page flip handle into cmdq cb irq callback will before cmdq flush ddp register into hardware, that will cause the display frame page flip event before it realy display out time

Signed-off-by: Yongqiang Niu yongqiang.niu@mediatek.com

drivers/gpu/drm/mediatek/mtk_drm_crtc.c | 33 +++++++++++++++++++++++++++++---- 1 file changed, 29 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c index bdd37ea..bece327 100644 --- a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c +++ b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c @@ -72,6 +72,13 @@ struct mtk_crtc_state { unsigned int pending_vrefresh; };

+#if IS_REACHABLE(CONFIG_MTK_CMDQ) +struct mtk_cmdq_cb_data {

•   struct cmdq_pkt                 *cmdq_handle;
  

•   struct mtk_drm_crtc             *mtk_crtc;
  

+}; +#endif

static inline struct mtk_drm_crtc *to_mtk_crtc(struct drm_crtc *c) { return container_of(c, struct mtk_drm_crtc, base); @@ -96,7 +103,6 @@ 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) {
            mtk_drm_crtc_finish_page_flip(mtk_crtc);
            mtk_crtc->pending_needs_vblank = false;
  

@@ -241,7 +247,19 @@ struct mtk_ddp_comp *mtk_drm_ddp_comp_for_plane(struct drm_crtc *crtc, #if IS_REACHABLE(CONFIG_MTK_CMDQ) static void ddp_cmdq_cb(struct cmdq_cb_data data) {

•   cmdq_pkt_destroy(data.data);
  

•   struct mtk_cmdq_cb_data *cb_data = data.data;
  

•   if (cb_data) {
  

•           struct mtk_drm_crtc *mtk_crtc = cb_data->mtk_crtc;
  

•           if (mtk_crtc)
  

•                   mtk_drm_finish_page_flip(mtk_crtc);
  

•           if (cb_data->cmdq_handle)
  

•                   cmdq_pkt_destroy(cb_data->cmdq_handle);
  

•           kfree(cb_data);
  

•   }
  

} #endif

@@ -481,13 +499,20 @@ static void mtk_drm_crtc_hw_config(struct mtk_drm_crtc *mtk_crtc) } #if IS_REACHABLE(CONFIG_MTK_CMDQ) if (mtk_crtc->cmdq_client) {

•           struct mtk_cmdq_cb_data *cb_data;
  

•           mbox_flush(mtk_crtc->cmdq_client->chan, 2000);
            cmdq_handle = cmdq_pkt_create(mtk_crtc->cmdq_client, PAGE_SIZE);
            cmdq_pkt_clear_event(cmdq_handle, mtk_crtc->cmdq_event);
            cmdq_pkt_wfe(cmdq_handle, mtk_crtc->cmdq_event, false);
            mtk_crtc_ddp_config(crtc, cmdq_handle);
            cmdq_pkt_finalize(cmdq_handle);
  

•           cmdq_pkt_flush_async(cmdq_handle, ddp_cmdq_cb, cmdq_handle);
  

•           cb_data = kmalloc(sizeof(*cb_data), GFP_KERNEL);
  

•           cb_data->cmdq_handle = cmdq_handle;
  

•           cb_data->mtk_crtc = mtk_crtc;
  

•           cmdq_pkt_flush_async(cmdq_handle, ddp_cmdq_cb, cb_data);
    }
  

#endif mutex_unlock(&mtk_crtc->hw_lock); @@ -674,7 +699,7 @@ void mtk_crtc_ddp_irq(struct drm_crtc *crtc, struct mtk_ddp_comp *comp) #endif mtk_crtc_ddp_config(crtc, NULL);

•   mtk_drm_finish_page_flip(mtk_crtc);
  

•   drm_crtc_handle_vblank(&mtk_crtc->base);
  

For CPU and shadow register case, where to handle page flip? The correct sequence should be:

1. set pending_needs_vblank to true 2. mtk_drm_crtc_hw_config 3. irq comes, handle page flip, and set pending_needs_vblank to false

But now irq comes before 2, so this patch want to fix this bug. I think shadow register also have this problem. The control flow of shadow register is similar to cmdq, so I would like to fix both problem in the same way.

Regards, Chun-Kuang.

}

static int mtk_drm_crtc_num_comp_planes(struct mtk_drm_crtc *mtk_crtc,

1.8.1.1.dirty