Patch "drm/mediatek: Move mtk_crtc_finish_page_flip() to ddp_cmdq_cb()" has been added to the 6.12-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    drm/mediatek: Move mtk_crtc_finish_page_flip() to ddp_cmdq_cb()

to the 6.12-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     drm-mediatek-move-mtk_crtc_finish_page_flip-to-ddp_c.patch
and it can be found in the queue-6.12 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 627e5705be01c40056bec33135177befa65e6d29
Author: Jason-JH.Lin <jason-jh.lin@xxxxxxxxxxxx>
Date:   Wed Dec 11 11:47:16 2024 +0800

    drm/mediatek: Move mtk_crtc_finish_page_flip() to ddp_cmdq_cb()
    
    [ Upstream commit da03801ad08f2488c01e684509cd89e1aa5d17ec ]
    
    mtk_crtc_finish_page_flip() is used to notify userspace that a
    page flip has been completed, allowing userspace to free the frame
    buffer of the last frame and commit the next frame.
    
    In MediaTek's hardware design for configuring display hardware by using
    GCE, `DRM_EVENT_FLIP_COMPLETE` should be notified to userspace after
    GCE has finished configuring all display hardware settings for each
    atomic_commit().
    
    Currently, mtk_crtc_finish_page_flip() cannot guarantee that GCE has
    configured all the display hardware settings of the last frame.
    Therefore, to increase the accuracy of the timing for notifying
    `DRM_EVENT_FLIP_COMPLETE` to userspace, mtk_crtc_finish_page_flip()
    should be moved to ddp_cmdq_cb().
    
    Fixes: 7f82d9c43879 ("drm/mediatek: Clear pending flag when cmdq packet is done")
    Signed-off-by: Jason-JH.Lin <jason-jh.lin@xxxxxxxxxxxx>
    Reviewed-by: CK Hu <ck.hu@xxxxxxxxxxxx>
    Link: https://patchwork.kernel.org/project/dri-devel/patch/20241211034716.29241-1-jason-jh.lin@xxxxxxxxxxxx/
    Signed-off-by: Chun-Kuang Hu <chunkuang.hu@xxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/gpu/drm/mediatek/mtk_crtc.c b/drivers/gpu/drm/mediatek/mtk_crtc.c
index eb0e1233ad04..5674f5707cca 100644
--- a/drivers/gpu/drm/mediatek/mtk_crtc.c
+++ b/drivers/gpu/drm/mediatek/mtk_crtc.c
@@ -112,6 +112,11 @@ static void mtk_drm_finish_page_flip(struct mtk_crtc *mtk_crtc)
 
 	drm_crtc_handle_vblank(&mtk_crtc->base);
 
+#if IS_REACHABLE(CONFIG_MTK_CMDQ)
+	if (mtk_crtc->cmdq_client.chan)
+		return;
+#endif
+
 	spin_lock_irqsave(&mtk_crtc->config_lock, flags);
 	if (!mtk_crtc->config_updating && mtk_crtc->pending_needs_vblank) {
 		mtk_crtc_finish_page_flip(mtk_crtc);
@@ -284,10 +289,8 @@ static void ddp_cmdq_cb(struct mbox_client *cl, void *mssg)
 	state = to_mtk_crtc_state(mtk_crtc->base.state);
 
 	spin_lock_irqsave(&mtk_crtc->config_lock, flags);
-	if (mtk_crtc->config_updating) {
-		spin_unlock_irqrestore(&mtk_crtc->config_lock, flags);
+	if (mtk_crtc->config_updating)
 		goto ddp_cmdq_cb_out;
-	}
 
 	state->pending_config = false;
 
@@ -315,10 +318,15 @@ static void ddp_cmdq_cb(struct mbox_client *cl, void *mssg)
 		mtk_crtc->pending_async_planes = false;
 	}
 
-	spin_unlock_irqrestore(&mtk_crtc->config_lock, flags);
-
 ddp_cmdq_cb_out:
 
+	if (mtk_crtc->pending_needs_vblank) {
+		mtk_crtc_finish_page_flip(mtk_crtc);
+		mtk_crtc->pending_needs_vblank = false;
+	}
+
+	spin_unlock_irqrestore(&mtk_crtc->config_lock, flags);
+
 	mtk_crtc->cmdq_vblank_cnt = 0;
 	wake_up(&mtk_crtc->cb_blocking_queue);
 }
@@ -606,13 +614,18 @@ static void mtk_crtc_update_config(struct mtk_crtc *mtk_crtc, bool needs_vblank)
 		 */
 		mtk_crtc->cmdq_vblank_cnt = 3;
 
+		spin_lock_irqsave(&mtk_crtc->config_lock, flags);
+		mtk_crtc->config_updating = false;
+		spin_unlock_irqrestore(&mtk_crtc->config_lock, flags);
+
 		mbox_send_message(mtk_crtc->cmdq_client.chan, cmdq_handle);
 		mbox_client_txdone(mtk_crtc->cmdq_client.chan, 0);
 	}
-#endif
+#else
 	spin_lock_irqsave(&mtk_crtc->config_lock, flags);
 	mtk_crtc->config_updating = false;
 	spin_unlock_irqrestore(&mtk_crtc->config_lock, flags);
+#endif
 
 	mutex_unlock(&mtk_crtc->hw_lock);
 }