Re: [PATCH v17 11/21] drm/mediatek: add display merge start/stop API for cmdq support

From: Matthias Brugger
Date: Mon Apr 25 2022 - 11:27:42 EST

On 25/04/2022 15:32, Chun-Kuang Hu wrote:
Hi, Matthias:

Matthias Brugger <matthias.bgg@xxxxxxxxx> 於 2022年4月22日 週五 下午7:48寫道:

On 16/04/2022 04:07, Nancy.Lin wrote:
Add merge start/stop API for cmdq support. The ovl_adaptor merges
are configured with each drm plane update. Need to enable/disable
merge with cmdq making sure all the settings taken effect in the
same vblank.

Signed-off-by: Nancy.Lin <nancy.lin@xxxxxxxxxxxx>
Reviewed-by: Chun-Kuang Hu <>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxx>
drivers/gpu/drm/mediatek/mtk_disp_drv.h | 2 ++
drivers/gpu/drm/mediatek/mtk_disp_merge.c | 20 +++++++++++++++++---
2 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_disp_drv.h b/drivers/gpu/drm/mediatek/mtk_disp_drv.h
index 53aa988dde3b..43a412525b75 100644
--- a/drivers/gpu/drm/mediatek/mtk_disp_drv.h
+++ b/drivers/gpu/drm/mediatek/mtk_disp_drv.h
@@ -66,6 +66,8 @@ void mtk_merge_stop(struct device *dev);
void mtk_merge_advance_config(struct device *dev, unsigned int l_w, unsigned int r_w,
unsigned int h, unsigned int vrefresh, unsigned int bpc,
struct cmdq_pkt *cmdq_pkt);
+void mtk_merge_start_cmdq(struct device *dev, struct cmdq_pkt *cmdq_pkt);
+void mtk_merge_stop_cmdq(struct device *dev, struct cmdq_pkt *cmdq_pkt);

void mtk_ovl_bgclr_in_on(struct device *dev);
void mtk_ovl_bgclr_in_off(struct device *dev);
diff --git a/drivers/gpu/drm/mediatek/mtk_disp_merge.c b/drivers/gpu/drm/mediatek/mtk_disp_merge.c
index 40da0555416d..c0d9b43b2a66 100644
--- a/drivers/gpu/drm/mediatek/mtk_disp_merge.c
+++ b/drivers/gpu/drm/mediatek/mtk_disp_merge.c
@@ -67,17 +67,31 @@ struct mtk_disp_merge {

void mtk_merge_start(struct device *dev)

Probably not my call, but wouldn't it make sense to enhance mtk_merge_start to
pass 'struct cmdq_pkt *cmdq_pkt' directly instead of adding this 'adapter'?

In [1], mtk_merge_start() should match the function prototype of
mtk_ddp_comp_funcs.start, so keep the non-cmdq interface.

Well other callbacks, namely config hass cmdq_pkt. So we could change the callback in a similar way is was done in
d0afe37f5209 ("drm/mediatek: support CMDQ interface in ddp component")

But as i said it's up to you. You are the maintainer.


static const struct mtk_ddp_comp_funcs ddp_merge = {
.clk_enable = mtk_merge_clk_enable,
.clk_disable = mtk_merge_clk_disable,
.start = mtk_merge_start,
.stop = mtk_merge_stop,
.config = mtk_merge_config,



In the end this is up to Chun-Kuang.


+ mtk_merge_start_cmdq(dev, NULL);
+void mtk_merge_stop(struct device *dev)
struct mtk_disp_merge *priv = dev_get_drvdata(dev);

- writel(MERGE_EN, priv->regs + DISP_REG_MERGE_CTRL);
+ mtk_merge_stop_cmdq(dev, NULL);

-void mtk_merge_stop(struct device *dev)
+void mtk_merge_start_cmdq(struct device *dev, struct cmdq_pkt *cmdq_pkt)
+ struct mtk_disp_merge *priv = dev_get_drvdata(dev);
+ mtk_ddp_write(cmdq_pkt, 1, &priv->cmdq_reg, priv->regs,
+void mtk_merge_stop_cmdq(struct device *dev, struct cmdq_pkt *cmdq_pkt)
struct mtk_disp_merge *priv = dev_get_drvdata(dev);

- writel(0x0, priv->regs + DISP_REG_MERGE_CTRL);
+ mtk_ddp_write(cmdq_pkt, 0, &priv->cmdq_reg, priv->regs,

static void mtk_merge_fifo_setting(struct mtk_disp_merge *priv,