Re: [PATCH v4 7/7] drm/mediatek: apply CMDQ control flow

[CK Hu]

Hi, Bibby:

On Thu, 2019-12-05 at 17:27 +0800, Bibby Hsieh wrote:
> Unlike other SoCs, MT8183 does not have "shadow"
> registers for performaing an atomic video mode
> set or page flip at vblank/vsync.
> 
> The CMDQ (Commend Queue) in MT8183 is used to help
> update all relevant display controller registers
> with critical time limation.

Reviewed-by: CK Hu <ck.hu@xxxxxxxxxxxx>
> 
> Signed-off-by: YT Shen <yt.shen@xxxxxxxxxxxx>
> Signed-off-by: CK Hu <ck.hu@xxxxxxxxxxxx>
> Signed-off-by: Philipp Zabel <p.zabel@xxxxxxxxxxxxxx>
> Signed-off-by: Bibby Hsieh <bibby.hsieh@xxxxxxxxxxxx>
> Signed-off-by: Yongqiang Niu <yongqiang.niu@xxxxxxxxxxxx>
> ---
>  drivers/gpu/drm/mediatek/mtk_drm_crtc.c | 56 +++++++++++++++++++++----
>  1 file changed, 49 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
> index 8c6231ed6f55..496dffe962af 100644
> --- a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
> +++ b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
> @@ -12,6 +12,8 @@
>  #include <drm/drm_plane_helper.h>
>  #include <drm/drm_probe_helper.h>
>  #include <drm/drm_vblank.h>
> +#include <linux/of_address.h>
> +#include <linux/soc/mediatek/mtk-cmdq.h>
>  
>  #include "mtk_drm_drv.h"
>  #include "mtk_drm_crtc.h"
> @@ -43,6 +45,9 @@ struct mtk_drm_crtc {
>  	bool				pending_planes;
>  	bool				pending_async_planes;
>  
> +	struct cmdq_client		*cmdq_client;
> +	u32				cmdq_event;
> +
>  	void __iomem			*config_regs;
>  	const struct mtk_mmsys_reg_data *mmsys_reg_data;
>  	struct mtk_disp_mutex		*mutex;
> @@ -234,6 +239,13 @@ struct mtk_ddp_comp *mtk_drm_ddp_comp_for_plane(struct drm_crtc *crtc,
>  	return NULL;
>  }
>  
> +#ifdef CONFIG_MTK_CMDQ
> +static void ddp_cmdq_cb(struct cmdq_cb_data data)
> +{
> +	cmdq_pkt_destroy(data.data);
> +}
> +#endif
> +
>  static int mtk_crtc_ddp_hw_init(struct mtk_drm_crtc *mtk_crtc)
>  {
>  	struct drm_crtc *crtc = &mtk_crtc->base;
> @@ -378,7 +390,8 @@ static void mtk_crtc_ddp_hw_fini(struct mtk_drm_crtc *mtk_crtc)
>  	}
>  }
>  
> -static void mtk_crtc_ddp_config(struct drm_crtc *crtc)
> +static void mtk_crtc_ddp_config(struct drm_crtc *crtc,
> +				struct cmdq_pkt *cmdq_handle)
>  {
>  	struct mtk_drm_crtc *mtk_crtc = to_mtk_crtc(crtc);
>  	struct mtk_crtc_state *state = to_mtk_crtc_state(mtk_crtc->base.state);
> @@ -394,7 +407,8 @@ static void mtk_crtc_ddp_config(struct drm_crtc *crtc)
>  	if (state->pending_config) {
>  		mtk_ddp_comp_config(comp, state->pending_width,
>  				    state->pending_height,
> -				    state->pending_vrefresh, 0, NULL);
> +				    state->pending_vrefresh, 0,
> +				    cmdq_handle);
>  
>  		state->pending_config = false;
>  	}
> @@ -414,7 +428,8 @@ static void mtk_crtc_ddp_config(struct drm_crtc *crtc)
>  
>  			if (comp)
>  				mtk_ddp_comp_layer_config(comp, local_layer,
> -							  plane_state, NULL);
> +							  plane_state,
> +							  cmdq_handle);
>  			plane_state->pending.config = false;
>  		}
>  		mtk_crtc->pending_planes = false;
> @@ -435,7 +450,8 @@ static void mtk_crtc_ddp_config(struct drm_crtc *crtc)
>  
>  			if (comp)
>  				mtk_ddp_comp_layer_config(comp, local_layer,
> -							  plane_state, NULL);
> +							  plane_state,
> +							  cmdq_handle);
>  			plane_state->pending.async_config = false;
>  		}
>  		mtk_crtc->pending_async_planes = false;
> @@ -444,6 +460,7 @@ static void mtk_crtc_ddp_config(struct drm_crtc *crtc)
>  
>  static void mtk_drm_crtc_hw_config(struct mtk_drm_crtc *mtk_crtc)
>  {
> +	struct cmdq_pkt *cmdq_handle;
>  	struct drm_crtc *crtc = &mtk_crtc->base;
>  	struct mtk_drm_private *priv = crtc->dev->dev_private;
>  	unsigned int pending_planes = 0, pending_async_planes = 0;
> @@ -472,9 +489,18 @@ static void mtk_drm_crtc_hw_config(struct mtk_drm_crtc *mtk_crtc)
>  
>  	if (priv->data->shadow_register) {
>  		mtk_disp_mutex_acquire(mtk_crtc->mutex);
> -		mtk_crtc_ddp_config(crtc);
> +		mtk_crtc_ddp_config(crtc, NULL);
>  		mtk_disp_mutex_release(mtk_crtc->mutex);
>  	}
> +#ifdef CONFIG_MTK_CMDQ
> +	if (mtk_crtc->cmdq_client) {
> +		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);
> +		mtk_crtc_ddp_config(crtc, cmdq_handle);
> +		cmdq_pkt_flush_async(cmdq_handle, ddp_cmdq_cb, cmdq_handle);
> +	}
> +#endif
>  	mutex_unlock(&mtk_crtc->hw_lock);
>  }
>  
> @@ -643,8 +669,8 @@ void mtk_crtc_ddp_irq(struct drm_crtc *crtc, struct mtk_ddp_comp *comp)
>  	struct mtk_drm_crtc *mtk_crtc = to_mtk_crtc(crtc);
>  	struct mtk_drm_private *priv = crtc->dev->dev_private;
>  
> -	if (!priv->data->shadow_register)
> -		mtk_crtc_ddp_config(crtc);
> +	if (!priv->data->shadow_register && !mtk_crtc->cmdq_client)
> +		mtk_crtc_ddp_config(crtc, NULL);
>  
>  	mtk_drm_finish_page_flip(mtk_crtc);
>  }
> @@ -787,5 +813,21 @@ int mtk_drm_crtc_create(struct drm_device *drm_dev,
>  	priv->num_pipes++;
>  	mutex_init(&mtk_crtc->hw_lock);
>  
> +#ifdef CONFIG_MTK_CMDQ
> +	mtk_crtc->cmdq_client =
> +			cmdq_mbox_create(dev, drm_crtc_index(&mtk_crtc->base),
> +					 2000);
> +	if (IS_ERR(mtk_crtc->cmdq_client)) {
> +		dev_dbg(dev, "mtk_crtc %d failed to create mailbox client, writing register by CPU now\n",
> +			drm_crtc_index(&mtk_crtc->base));
> +		mtk_crtc->cmdq_client = NULL;
> +	}
> +	ret = of_property_read_u32_index(dev->of_node, "mediatek,gce-events",
> +					 drm_crtc_index(&mtk_crtc->base),
> +					 &mtk_crtc->cmdq_event);
> +	if (ret)
> +		dev_dbg(dev, "mtk_crtc %d failed to get mediatek,gce-events property\n",
> +			drm_crtc_index(&mtk_crtc->base));
> +#endif
>  	return 0;
>  }