Message-ID: <1567151915.31732.3.camel@mtksdaap41>
Date:   Fri, 30 Aug 2019 15:58:35 +0800
From:   CK Hu <ck.hu@...iatek.com>
To:     Bibby Hsieh <bibby.hsieh@...iatek.com>
CC:     David Airlie <airlied@...ux.ie>,
        Matthias Brugger <matthias.bgg@...il.com>,
        Daniel Vetter <daniel.vetter@...ll.ch>,
        <dri-devel@...ts.freedesktop.org>,
        <linux-mediatek@...ts.infradead.org>,
        Philipp Zabel <p.zabel@...gutronix.de>,
        YT Shen <yt.shen@...iatek.com>,
        Thierry Reding <thierry.reding@...il.com>,
        <linux-arm-kernel@...ts.infradead.org>, <tfiga@...omium.org>,
        <drinkcat@...omium.org>, <linux-kernel@...r.kernel.org>,
        Yongqiang Niu <yongqiang.niu@...iatek.com>
Subject: Re: [PATCH 2/2] drm/mediatek: Apply CMDQ control flow

Hi, Bibby:

On Fri, 2019-08-30 at 15:41 +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.
> 
> Signed-off-by: YT Shen <yt.shen@...iatek.com>
> Signed-off-by: CK Hu <ck.hu@...iatek.com>
> Signed-off-by: Philipp Zabel <p.zabel@...gutronix.de>
> Signed-off-by: Bibby Hsieh <bibby.hsieh@...iatek.com>
> Signed-off-by: Yongqiang Niu <yongqiang.niu@...iatek.com>
> ---
>  drivers/gpu/drm/mediatek/mtk_drm_crtc.c     | 190 +++++++++++++++++---
>  drivers/gpu/drm/mediatek/mtk_drm_crtc.h     |   2 +
>  drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c |  34 ++++
>  drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.h |   2 +
>  drivers/gpu/drm/mediatek/mtk_drm_plane.c    |   4 +
>  5 files changed, 206 insertions(+), 26 deletions(-)
> 
> diff --git a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
> index 092e502ed27b..329ca5a14c39 100644
> --- a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
> +++ b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
> @@ -10,7 +10,9 @@
>  #include <drm/drm_plane_helper.h>
>  #include <drm/drm_probe_helper.h>
>  #include <linux/clk.h>
> +#include <linux/of_address.h>
>  #include <linux/pm_runtime.h>
> +#include <linux/soc/mediatek/mtk-cmdq.h>
>  
>  #include "mtk_drm_drv.h"
>  #include "mtk_drm_crtc.h"
> @@ -41,6 +43,10 @@ struct mtk_drm_crtc {
>  	unsigned int			layer_nr;
>  	bool				pending_planes;
>  	bool                            cursor_update;
> +
> +	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;
> @@ -57,6 +63,12 @@ struct mtk_crtc_state {
>  	unsigned int			pending_width;
>  	unsigned int			pending_height;
>  	unsigned int			pending_vrefresh;
> +	struct cmdq_pkt			*cmdq_handle;
> +};
> +
> +struct mtk_cmdq_cb_data {
> +	struct drm_crtc_state		*state;
> +	struct cmdq_pkt			*cmdq_handle;
>  };
>  
>  static inline struct mtk_drm_crtc *to_mtk_crtc(struct drm_crtc *c)
> @@ -208,6 +220,46 @@ static void mtk_crtc_ddp_clk_disable(struct mtk_drm_crtc *mtk_crtc)
>  		clk_disable_unprepare(mtk_crtc->ddp_comp[i]->clk);
>  }
>  
> +static void ddp_cmdq_cursor_cb(struct cmdq_cb_data data)
> +{
> +
> +#if IS_ENABLED(CONFIG_MTK_CMDQ)

I would like the whole ddp_cmdq_cursor_cb() and ddp_cmdq_cb() inside
this part.

> +	struct mtk_cmdq_cb_data *cb_data = data.data;
> +
> +	DRM_DEBUG_DRIVER("%s\n", __func__);
> +
> +	cmdq_pkt_destroy(cb_data->cmdq_handle);
> +	kfree(cb_data);
> +#endif
> +
> +}
> +
> +static void ddp_cmdq_cb(struct cmdq_cb_data data)
> +{
> +
> +#if IS_ENABLED(CONFIG_MTK_CMDQ)
> +	struct mtk_cmdq_cb_data *cb_data = data.data;
> +	struct drm_crtc_state *crtc_state = cb_data->state;
> +	struct drm_atomic_state *atomic_state = crtc_state->state;
> +	struct drm_crtc *crtc = crtc_state->crtc;
> +	struct mtk_drm_crtc *mtk_crtc = to_mtk_crtc(crtc);
> +
> +	DRM_DEBUG_DRIVER("%s\n", __func__);
> +
> +	if (mtk_crtc->pending_needs_vblank) {
> +		/* cmdq_vblank_event must be read after cmdq_needs_event */
> +		smp_rmb();
> +
> +		mtk_drm_crtc_finish_page_flip(mtk_crtc);
> +		mtk_crtc->pending_needs_vblank = false;
> +	}
> +	mtk_atomic_state_put_queue(atomic_state);
> +	cmdq_pkt_destroy(cb_data->cmdq_handle);
> +	kfree(cb_data);
> +#endif
> +
> +}
> +
>  static int mtk_crtc_ddp_hw_init(struct mtk_drm_crtc *mtk_crtc)
>  {
>  	struct drm_crtc *crtc = &mtk_crtc->base;
> @@ -283,7 +335,8 @@ static int mtk_crtc_ddp_hw_init(struct mtk_drm_crtc *mtk_crtc)
>  		if (prev == DDP_COMPONENT_OVL0)
>  			mtk_ddp_comp_bgclr_in_on(comp);
>  
> -		mtk_ddp_comp_config(comp, width, height, vrefresh, bpc);
> +		mtk_ddp_comp_config(comp, width, height,
> +				    vrefresh, bpc, NULL);
>  		mtk_ddp_comp_start(comp);
>  	}
>  
> @@ -303,7 +356,7 @@ static int mtk_crtc_ddp_hw_init(struct mtk_drm_crtc *mtk_crtc)
>  		} else
>  			local_layer = i;
>  		mtk_ddp_comp_layer_config(comp, local_layer,
> -					  plane_state);
> +					  plane_state, NULL);
>  	}
>  
>  	return 0;
> @@ -361,7 +414,7 @@ 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);
> +				    state->pending_vrefresh, 0, NULL);
>  
>  		state->pending_config = false;
>  	}
> @@ -381,7 +434,7 @@ static void mtk_crtc_ddp_config(struct drm_crtc *crtc)
>  					local_layer = i;
>  
>  				mtk_ddp_comp_layer_config(comp, local_layer,
> -							  plane_state);
> +							  plane_state, NULL);
>  				plane_state->pending.config = false;
>  			}
>  		}
> @@ -405,26 +458,69 @@ void mtk_drm_crtc_cursor_update(struct drm_crtc *crtc, struct drm_plane *plane,
>  		return;
>  
>  	mutex_lock(&priv->hw_lock);
> -	plane_helper_funcs->atomic_update(plane, plane_state);
> -	for (i = 0; i < mtk_crtc->layer_nr; i++) {
> -		struct drm_plane *plane = &mtk_crtc->planes[i];
> -		struct mtk_plane_state *plane_state;
> +	if (IS_ENABLED(CONFIG_MTK_CMDQ) && mtk_crtc->cmdq_client) {
> +		struct mtk_crtc_state *mtk_crtc_state =
> +				to_mtk_crtc_state(crtc->state);
> +		struct mtk_cmdq_cb_data *cb_data;
> +
> +		mtk_crtc_state->cmdq_handle =
> +				cmdq_pkt_create(mtk_crtc->cmdq_client,
> +						PAGE_SIZE);
> +		cmdq_pkt_clear_event(mtk_crtc_state->cmdq_handle,
> +				     mtk_crtc->cmdq_event);
> +		cmdq_pkt_wfe(mtk_crtc_state->cmdq_handle, mtk_crtc->cmdq_event);
> +		plane_helper_funcs->atomic_update(plane, plane_state);
> +		cb_data = kmalloc(sizeof(*cb_data), GFP_KERNEL);
> +		cb_data->cmdq_handle = mtk_crtc_state->cmdq_handle;
> +		cmdq_pkt_flush_async(mtk_crtc_state->cmdq_handle,
> +				     ddp_cmdq_cursor_cb, cb_data);
> +	} else {
> +		plane_helper_funcs->atomic_update(plane, plane_state);
>  
> -		plane_state = to_mtk_plane_state(plane->state);
> -		if (plane_state->pending.dirty) {
> -			plane_state->pending.config = true;
> -			plane_state->pending.dirty = false;
> +		for (i = 0; i < mtk_crtc->layer_nr; i++) {
> +			struct drm_plane *plane = &mtk_crtc->planes[i];
> +			struct mtk_plane_state *plane_state;
> +
> +			plane_state = to_mtk_plane_state(plane->state);
> +			if (plane_state->pending.dirty) {
> +				plane_state->pending.config = true;
> +				plane_state->pending.dirty = false;
> +			}
> +		}
> +		mtk_crtc->pending_planes = true;
> +		mtk_crtc->cursor_update = true;
> +		if (priv->data->shadow_register) {
> +			mtk_disp_mutex_acquire(mtk_crtc->mutex);
> +			mtk_crtc_ddp_config(crtc);
> +			mtk_disp_mutex_release(mtk_crtc->mutex);
>  		}
>  	}
> -	mtk_crtc->pending_planes = true;
> -	mtk_crtc->cursor_update = true;
> +	mutex_unlock(&priv->hw_lock);
> +}
>  
> -	if (priv->data->shadow_register) {
> -		mtk_disp_mutex_acquire(mtk_crtc->mutex);
> -		mtk_crtc_ddp_config(crtc);
> -		mtk_disp_mutex_release(mtk_crtc->mutex);

My idea for the control flow is:

1. In the end of mtk_drm_crtc_atomic_flush(), do something like shadow
register control,

if (priv->data->cmdq) {
    /* abort cmd in queue */
    /* Call mtk_crtc_ddp_config() to generate command */
    /* send cmd to queue */
}
2. In mtk_crtc_ddp_config(), if cmdq is used, state->pending_config and
mtk_crtc->pending_planes would not be set to false. These two variable
would be set to false in cmdq callback.

Regards,
CK

> +void mtk_drm_crtc_plane_update(struct drm_crtc *crtc, struct drm_plane *plane,
> +			       struct mtk_plane_state *state)
> +{
> +	struct mtk_drm_crtc *mtk_crtc = to_mtk_crtc(crtc);
> +	struct mtk_ddp_comp *comp = mtk_crtc->ddp_comp[0];
> +	struct drm_crtc_state *crtc_state = crtc->state;
> +	struct mtk_crtc_state *mtk_crtc_state = to_mtk_crtc_state(crtc_state);
> +	struct cmdq_pkt *cmdq_handle = mtk_crtc_state->cmdq_handle;
> +	unsigned int comp_layer_nr = mtk_ddp_comp_layer_nr(comp);
> +	unsigned int local_layer;
> +	unsigned int plane_index = plane - mtk_crtc->planes;
> +
> +	DRM_DEBUG_DRIVER("%s\n", __func__);
> +	if (mtk_crtc->cmdq_client) {
> +		if (plane_index >= comp_layer_nr) {
> +			comp = mtk_crtc->ddp_comp[1];
> +			local_layer = plane_index - comp_layer_nr;
> +		} else {
> +			local_layer = plane_index;
> +		}
> +		mtk_ddp_comp_layer_config(comp, local_layer, state,
> +					  cmdq_handle);
>  	}
> -	mutex_unlock(&priv->hw_lock);
>  }
>  
>  static void mtk_drm_crtc_atomic_enable(struct drm_crtc *crtc,
> @@ -487,6 +583,15 @@ static void mtk_drm_crtc_atomic_begin(struct drm_crtc *crtc,
>  		WARN_ON(drm_crtc_vblank_get(crtc) != 0);
>  		mtk_crtc->event = state->base.event;
>  		state->base.event = NULL;
> +		/* Make sure the above parameter is set before update */
> +		smp_wmb();
> +		mtk_crtc->pending_needs_vblank = true;
> +	}
> +	if (IS_ENABLED(CONFIG_MTK_CMDQ) && mtk_crtc->cmdq_client) {
> +		state->cmdq_handle = cmdq_pkt_create(mtk_crtc->cmdq_client,
> +						     PAGE_SIZE);
> +		cmdq_pkt_clear_event(state->cmdq_handle, mtk_crtc->cmdq_event);
> +		cmdq_pkt_wfe(state->cmdq_handle, mtk_crtc->cmdq_event);
>  	}
>  }
>  
> @@ -494,13 +599,29 @@ static void mtk_drm_crtc_atomic_flush(struct drm_crtc *crtc,
>  				      struct drm_crtc_state *old_crtc_state)
>  {
>  	struct drm_atomic_state *old_atomic_state = old_crtc_state->state;
> +	struct drm_crtc_state *crtc_state = crtc->state;
> +	struct mtk_crtc_state *state = to_mtk_crtc_state(crtc_state);
> +	struct cmdq_pkt *cmdq_handle = state->cmdq_handle;
>  	struct mtk_drm_crtc *mtk_crtc = to_mtk_crtc(crtc);
>  	struct mtk_drm_private *priv = crtc->dev->dev_private;
> +	struct mtk_cmdq_cb_data *cb_data;
>  	unsigned int pending_planes = 0;
>  	int i;
>  
> -	if (mtk_crtc->event)
> -		mtk_crtc->pending_needs_vblank = true;
> +	DRM_DEBUG_DRIVER("[CRTC:%u] [STATE:%p(%p)->%p(%p)]\n", crtc->base.id,
> +			 old_crtc_state, old_crtc_state->state,
> +			 crtc_state, crtc_state->state);
> +
> +	if (IS_ENABLED(CONFIG_MTK_CMDQ) && mtk_crtc->cmdq_client) {
> +		drm_atomic_state_get(old_atomic_state);
> +		cb_data = kmalloc(sizeof(*cb_data), GFP_KERNEL);
> +		cb_data->state = old_crtc_state;
> +		cb_data->cmdq_handle = cmdq_handle;
> +		cmdq_pkt_flush_async(cmdq_handle, ddp_cmdq_cb, cb_data);
> +
> +		return;
> +	}
> +
>  	for (i = 0; i < mtk_crtc->layer_nr; i++) {
>  		struct drm_plane *plane = &mtk_crtc->planes[i];
>  		struct mtk_plane_state *plane_state;
> @@ -521,7 +642,8 @@ static void mtk_drm_crtc_atomic_flush(struct drm_crtc *crtc,
>  
>  	if (crtc->state->color_mgmt_changed)
>  		for (i = 0; i < mtk_crtc->ddp_comp_nr; i++)
> -			mtk_ddp_gamma_set(mtk_crtc->ddp_comp[i], crtc->state);
> +			mtk_ddp_gamma_set(mtk_crtc->ddp_comp[i],
> +					  crtc->state, NULL);
>  
>  	if (priv->data->shadow_register) {
>  		mtk_disp_mutex_acquire(mtk_crtc->mutex);
> @@ -578,10 +700,13 @@ 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);
> -
> -	mtk_drm_finish_page_flip(mtk_crtc);
> +	if (mtk_crtc->cmdq_client) {
> +		drm_crtc_handle_vblank(crtc);
> +	} else {
> +		if (!priv->data->shadow_register)
> +			mtk_crtc_ddp_config(crtc);
> +		mtk_drm_finish_page_flip(mtk_crtc);
> +	}
>  }
>  
>  int mtk_drm_crtc_create(struct drm_device *drm_dev,
> @@ -678,5 +803,18 @@ int mtk_drm_crtc_create(struct drm_device *drm_dev,
>  	drm_crtc_enable_color_mgmt(&mtk_crtc->base, 0, false, MTK_LUT_SIZE);
>  	priv->num_pipes++;
>  
> +	if (IS_ENABLED(CONFIG_MTK_CMDQ)) {
> +		mtk_crtc->cmdq_client = cmdq_mbox_create(dev,
> +				drm_crtc_index(&mtk_crtc->base), 2000);
> +		of_property_read_u32_index(dev->of_node, "mediatek,gce-events",
> +					   drm_crtc_index(&mtk_crtc->base),
> +					   &mtk_crtc->cmdq_event);
> +		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;
> +		}
> +	}
> +
>  	return 0;
>  }
> diff --git a/drivers/gpu/drm/mediatek/mtk_drm_crtc.h b/drivers/gpu/drm/mediatek/mtk_drm_crtc.h
> index 46e903be68ec..6b2423c88416 100644
> --- a/drivers/gpu/drm/mediatek/mtk_drm_crtc.h
> +++ b/drivers/gpu/drm/mediatek/mtk_drm_crtc.h
> @@ -19,6 +19,8 @@ void mtk_crtc_ddp_irq(struct drm_crtc *crtc, struct mtk_ddp_comp *comp);
>  int mtk_drm_crtc_create(struct drm_device *drm_dev,
>  			const enum mtk_ddp_comp_id *path,
>  			unsigned int path_len);
> +void mtk_drm_crtc_plane_update(struct drm_crtc *crtc, struct drm_plane *plane,
> +			       struct mtk_plane_state *state);
>  void mtk_drm_crtc_cursor_update(struct drm_crtc *crtc, struct drm_plane *plane,
>  				struct drm_plane_state *plane_state);
>  
> diff --git a/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c b/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c
> index 76416c1cbb28..056ebc6a8199 100644
> --- a/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c
> +++ b/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c
> @@ -395,6 +395,40 @@ int mtk_ddp_comp_init(struct device *dev, struct device_node *node,
>  	if (IS_ERR(comp->clk))
>  		return PTR_ERR(comp->clk);
>  
> +	if (IS_ENABLED(CONFIG_MTK_CMDQ)) {
> +		struct platform_device *comp_pdev;
> +		struct resource res;
> +		struct cmdq_client_reg *cmdq_reg;
> +		int ret = 0;
> +
> +		if (of_address_to_resource(node, 0, &res) != 0) {
> +			dev_err(dev, "Missing reg in %s node\n",
> +				node->full_name);
> +			return -EINVAL;
> +		}
> +		comp->regs_pa = res.start;
> +
> +		comp_pdev = of_find_device_by_node(node);
> +		if (!comp_pdev) {
> +			dev_warn(dev, "Waiting for component device %s\n",
> +				 node->full_name);
> +			return -EPROBE_DEFER;
> +		}
> +
> +		cmdq_reg = kzalloc(sizeof(*cmdq_reg), GFP_KERNEL);
> +		if (!cmdq_reg)
> +			return -EINVAL;
> +
> +		ret = cmdq_dev_get_client_reg(&comp_pdev->dev, cmdq_reg, 0);
> +		if (ret != 0)
> +			dev_dbg(&comp_pdev->dev,
> +				"get mediatek,gce-client-reg fail!\n");
> +		else
> +			comp->subsys = cmdq_reg->subsys;
> +
> +		kfree(cmdq_reg);
> +	}
> +
>  	return 0;
>  }
>  
> diff --git a/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.h b/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.h
> index 6bbc35f92815..0faec2dad5a3 100644
> --- a/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.h
> +++ b/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.h
> @@ -99,6 +99,8 @@ struct mtk_ddp_comp {
>  	int irq;
>  	enum mtk_ddp_comp_id id;
>  	const struct mtk_ddp_comp_funcs *funcs;
> +	resource_size_t regs_pa;
> +	u8 subsys;
>  };
>  
>  static inline void mtk_ddp_comp_config(struct mtk_ddp_comp *comp,
> diff --git a/drivers/gpu/drm/mediatek/mtk_drm_plane.c b/drivers/gpu/drm/mediatek/mtk_drm_plane.c
> index 59dbdaf07425..ef46c0f43039 100644
> --- a/drivers/gpu/drm/mediatek/mtk_drm_plane.c
> +++ b/drivers/gpu/drm/mediatek/mtk_drm_plane.c
> @@ -202,6 +202,8 @@ static void mtk_plane_atomic_update(struct drm_plane *plane,
>  	state->pending.height = drm_rect_height(&plane->state->dst);
>  	wmb(); /* Make sure the above parameters are set before update */
>  	state->pending.dirty = true;
> +
> +	mtk_drm_crtc_plane_update(crtc, plane, state);
>  }
>  
>  static void mtk_plane_atomic_disable(struct drm_plane *plane,
> @@ -212,6 +214,8 @@ static void mtk_plane_atomic_disable(struct drm_plane *plane,
>  	state->pending.enable = false;
>  	wmb(); /* Make sure the above parameter is set before update */
>  	state->pending.dirty = true;
> +	/* Fetch CRTC from old plane state when disabling. */
> +	mtk_drm_crtc_plane_update(old_state->crtc, plane, state);
>  }
>  
>  static const struct drm_plane_helper_funcs mtk_plane_helper_funcs = {

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