Re: [PATCH v1 6/6] drm/mediatek: apply CMDQ control flow

[CK Hu]

Hi, Bibby:

On Tue, 2019-12-03 at 13:58 +0800, Bibby Hsieh wrote:
> On Tue, 2019-12-03 at 09:38 +0800, CK Hu wrote:
> > Hi, Bibby:
> > 
> > On Thu, 2019-11-28 at 10:42 +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@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     | 86 ++++++++++++++++++++-
> > >  drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c | 31 ++++++++
> > >  2 files changed, 113 insertions(+), 4 deletions(-)
> > > 
> > > diff --git a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
> > > index fcf4e755e0bd..1b4e537ac3c1 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"
> > > @@ -42,6 +44,9 @@ struct mtk_drm_crtc {
> > >  	unsigned int			layer_nr;
> > >  	bool				pending_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;
> > > @@ -56,6 +61,11 @@ 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 cmdq_pkt			*cmdq_handle;
> > >  };
> > >  
> > >  static inline struct mtk_drm_crtc *to_mtk_crtc(struct drm_crtc *c)
> > > @@ -229,6 +239,46 @@ 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)
> > > +{
> > > +	struct mtk_cmdq_cb_data *cb_data = data.data;
> > > +
> > > +	cmdq_pkt_destroy(cb_data->cmdq_handle);
> > > +	kfree(cb_data);
> > > +}
> > > +
> > > +static void mtk_cmdq_acquire(struct drm_crtc *crtc)
> > > +{
> > > +	struct mtk_crtc_state *mtk_crtc_state =
> > > +			to_mtk_crtc_state(crtc->state);
> > > +	struct mtk_drm_crtc *mtk_crtc = to_mtk_crtc(crtc);
> > > +
> > > +	mtk_crtc_state->cmdq_handle =
> > > +			cmdq_pkt_create(mtk_crtc->cmdq_client,
> > > +					PAGE_SIZE);
> > 
> > I would like to remove atomic feature in cmdq driver and drm driver
> > could reuse the pkt. Please refer to [1] for detail.
> > 
> > [1]
> > http://lists.infradead.org/pipermail/linux-mediatek/2019-January/016866.html
> Hi, CK,
> 
> Thanks for all the comments.
> I will change them in my next version.
> 
> About the atomic feature removing, I think we already made note at here.
> Let's fix them after the atomic feature removed really.

Removing atomic feature would modify the device tree, and I'm worry that
device tree setting could not be modified at that time. I think we could
modify the device tree now because there no client use cmdq in upstream.

Regards,
CK

> 
> Bibby
> > 
> > > +	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);
> > > +}
> > > +
> > > +static void mtk_cmdq_release(struct drm_crtc *crtc)
> > > +{
> > > +	struct mtk_crtc_state *mtk_crtc_state =
> > > +			to_mtk_crtc_state(crtc->state);
> > > +	struct mtk_cmdq_cb_data *cb_data;
> > > +
> > > +	cb_data = kmalloc(sizeof(*cb_data), GFP_KERNEL);
> > > +	if (!cb_data) {
> > > +		DRM_DEV_ERROR(crtc->dev->dev, "Failed to alloc cb_data\n");
> > > +		return;
> > > +	}
> > > +
> > > +	cb_data->cmdq_handle = mtk_crtc_state->cmdq_handle;
> > > +	cmdq_pkt_flush_async(mtk_crtc_state->cmdq_handle,
> > > +			     ddp_cmdq_cb, cb_data);
> > > +}
> > > +#endif
> > >  static int mtk_crtc_ddp_hw_init(struct mtk_drm_crtc *mtk_crtc)
> > >  {
> > >  	struct drm_crtc *crtc = &mtk_crtc->base;
> > > @@ -383,7 +433,8 @@ 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,
> > > +				    state->cmdq_handle);
> > >  
> > >  		state->pending_config = false;
> > >  	}
> > > @@ -403,7 +454,8 @@ 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,
> > > +							  state->cmdq_handle);
> > >  			plane_state->pending.config = false;
> > >  		}
> > >  		mtk_crtc->pending_planes = false;
> > > @@ -454,6 +506,13 @@ void mtk_drm_crtc_cursor_update(struct drm_crtc *crtc, struct drm_plane *plane,
> > >  		mtk_crtc_ddp_config(crtc);
> > >  		mtk_disp_mutex_release(mtk_crtc->mutex);
> > >  	}
> > > +#ifdef CONFIG_MTK_CMDQ
> > > +	if (mtk_crtc->cmdq_client) {
> > > +		mtk_cmdq_acquire(crtc);
> > > +		mtk_crtc_ddp_config(crtc);
> > > +		mtk_cmdq_release(crtc);
> > > +	}
> > > +#endif
> > >  	mutex_unlock(&priv->hw_lock);
> > >  }
> > >  
> > > @@ -570,6 +629,13 @@ static void mtk_drm_crtc_atomic_flush(struct drm_crtc *crtc,
> > >  		mtk_crtc_ddp_config(crtc);
> > >  		mtk_disp_mutex_release(mtk_crtc->mutex);
> > >  	}
> > > +#ifdef CONFIG_MTK_CMDQ
> > > +	if (mtk_crtc->cmdq_client) {
> > > +		mtk_cmdq_acquire(crtc);
> > > +		mtk_crtc_ddp_config(crtc);
> > > +		mtk_cmdq_release(crtc);
> > > +	}
> > > +#endif
> > 
> > This part is almost the same as the one in mtk_drm_crtc_cursor_update(),
> > try to merge them.
> > 
> > >  }
> > >  
> > >  static const struct drm_crtc_funcs mtk_crtc_funcs = {
> > > @@ -619,7 +685,7 @@ 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)
> > > +	if (!priv->data->shadow_register && !mtk_crtc->cmdq_client)
> > >  		mtk_crtc_ddp_config(crtc);
> > >  
> > >  	mtk_drm_finish_page_flip(mtk_crtc);
> > > @@ -761,6 +827,18 @@ int mtk_drm_crtc_create(struct drm_device *drm_dev,
> > >  	drm_mode_crtc_set_gamma_size(&mtk_crtc->base, MTK_LUT_SIZE);
> > >  	drm_crtc_enable_color_mgmt(&mtk_crtc->base, 0, false, MTK_LUT_SIZE);
> > >  	priv->num_pipes++;
> > > -
> > > +#ifdef 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;
> > > +	}
> > > +#endif
> > >  	return 0;
> > >  }
> > > diff --git a/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c b/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c
> > > index 6d0f349ddf82..9cc12af2bc06 100644
> > > --- a/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c
> > > +++ b/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c
> > > @@ -370,6 +370,9 @@ int mtk_ddp_comp_init(struct device *dev, struct device_node *node,
> > >  		      const struct mtk_ddp_comp_funcs *funcs)
> > >  {
> > >  	struct platform_device *comp_pdev;
> > > +	struct resource res;
> > > +	struct cmdq_client_reg *cmdq_reg;
> > > +	int ret = 0;
> > >  
> > >  	if (comp_id < 0 || comp_id >= DDP_COMPONENT_ID_MAX)
> > >  		return -EINVAL;
> > > @@ -404,6 +407,34 @@ int mtk_ddp_comp_init(struct device *dev, struct device_node *node,
> > >  	}
> > >  	comp->dev = &comp_pdev->dev;
> > >  
> > > +#ifdef CONFIG_MTK_CMDQ
> > > +	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);
> > > +#endif
> > 
> > I would like to move this part to the patch "drm/mediatek: support CMDQ
> > interface in ddp component".
> > 
> > Regards,
> > CK
> > 
> > >  	return 0;
> > >  }
> > >  
> > 
> > 
> 
>