Subject: Re: [PATCH v3 12/14] drm/mediatek: Add pm runtime support for ovl and rdma

From: CK Hu <[email-masked]>
Date: Mon, 16 Sep 2019 15:55:40 +0800

Hi, Yong:

On Tue, 2019-09-03 at 17:37 +0800, Yong Wu wrote:
> From: Yongqiang Niu <[email-masked]>
> 
> Display use the dispsys device to call pm_rumtime_get_sync before.
> This patch add pm_runtime_xx with ovl and rdma device which has linked
> with larb0, then it will enable the correpsonding larb0 clock
> automatically by the device link.

This patch should be applied before "drm/mediatek: Get rid of
mtk_smi_larb_get/put". If before that patch, this patch is a preparation
of that patch. If after that patch, this patch is a bug fix of that
patch. Why let bug happen?

> 
> Signed-off-by: Yongqiang Niu <[email-masked]>
> Signed-off-by: Yong Wu <[email-masked]>
> ---
>  drivers/gpu/drm/mediatek/mtk_disp_ovl.c     |  5 +++++
>  drivers/gpu/drm/mediatek/mtk_disp_rdma.c    |  5 +++++
>  drivers/gpu/drm/mediatek/mtk_drm_crtc.c     | 18 ++++++++++++++++--
>  drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c |  9 +++++++++
>  drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.h |  1 +
>  5 files changed, 36 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/mediatek/mtk_disp_ovl.c b/drivers/gpu/drm/mediatek/mtk_disp_ovl.c
> index c4f07c2..51958cf 100644
> --- a/drivers/gpu/drm/mediatek/mtk_disp_ovl.c
> +++ b/drivers/gpu/drm/mediatek/mtk_disp_ovl.c
> @@ -9,6 +9,7 @@
>  #include <linux/of_device.h>
>  #include <linux/of_irq.h>
>  #include <linux/platform_device.h>
> +#include <linux/pm_runtime.h>
>  
>  #include "mtk_drm_crtc.h"
>  #include "mtk_drm_ddp_comp.h"
> @@ -300,6 +301,8 @@ static int mtk_disp_ovl_probe(struct platform_device *pdev)
>  		return ret;
>  	}
>  
> +	pm_runtime_enable(dev);
> +
>  	ret = component_add(dev, &mtk_disp_ovl_component_ops);
>  	if (ret)
>  		dev_err(dev, "Failed to add component: %d\n", ret);

This error should do some error handling to undo pm_runtime_enable().

> @@ -311,6 +314,8 @@ static int mtk_disp_ovl_remove(struct platform_device *pdev)
>  {
>  	component_del(&pdev->dev, &mtk_disp_ovl_component_ops);
>  
> +	pm_runtime_disable(&pdev->dev);
> +
>  	return 0;
>  }
>  
> diff --git a/drivers/gpu/drm/mediatek/mtk_disp_rdma.c b/drivers/gpu/drm/mediatek/mtk_disp_rdma.c
> index 9a6f0a2..15e5c3a 100644
> --- a/drivers/gpu/drm/mediatek/mtk_disp_rdma.c
> +++ b/drivers/gpu/drm/mediatek/mtk_disp_rdma.c
> @@ -9,6 +9,7 @@
>  #include <linux/of_device.h>
>  #include <linux/of_irq.h>
>  #include <linux/platform_device.h>
> +#include <linux/pm_runtime.h>
>  
>  #include "mtk_drm_crtc.h"
>  #include "mtk_drm_ddp_comp.h"
> @@ -306,6 +307,8 @@ static int mtk_disp_rdma_probe(struct platform_device *pdev)
>  
>  	platform_set_drvdata(pdev, priv);
>  
> +	pm_runtime_enable(dev);
> +
>  	ret = component_add(dev, &mtk_disp_rdma_component_ops);
>  	if (ret)
>  		dev_err(dev, "Failed to add component: %d\n", ret);

Ditto.

> @@ -317,6 +320,8 @@ static int mtk_disp_rdma_remove(struct platform_device *pdev)
>  {
>  	component_del(&pdev->dev, &mtk_disp_rdma_component_ops);
>  
> +	pm_runtime_disable(&pdev->dev);
> +
>  	return 0;
>  }
>  
> diff --git a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
> index c1e891e..daf002e 100644
> --- a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
> +++ b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
> @@ -358,13 +358,21 @@ static void mtk_drm_crtc_atomic_enable(struct drm_crtc *crtc,
>  				       struct drm_crtc_state *old_state)
>  {
>  	struct mtk_drm_crtc *mtk_crtc = to_mtk_crtc(crtc);
> +	struct mtk_ddp_comp *comp = mtk_crtc->ddp_comp[0];
>  	int ret;
>  
>  	DRM_DEBUG_DRIVER("%s %d\n", __func__, crtc->base.id);
>  
> +	ret = pm_runtime_get_sync(comp->dev);
> +	if (ret < 0)
> +		DRM_DEV_ERROR(comp->dev, "Failed to enable power domain: %d\n",
> +			      ret);
> +
>  	ret = mtk_crtc_ddp_hw_init(mtk_crtc);
> -	if (ret)
> +	if (ret) {
> +		pm_runtime_put(comp->dev);
>  		return;
> +	}
>  
>  	drm_crtc_vblank_on(crtc);
>  	mtk_crtc->enabled = true;
> @@ -374,7 +382,8 @@ static void mtk_drm_crtc_atomic_disable(struct drm_crtc *crtc,
>  					struct drm_crtc_state *old_state)
>  {
>  	struct mtk_drm_crtc *mtk_crtc = to_mtk_crtc(crtc);
> -	int i;
> +	struct mtk_ddp_comp *comp = mtk_crtc->ddp_comp[0];
> +	int i, ret;
>  
>  	DRM_DEBUG_DRIVER("%s %d\n", __func__, crtc->base.id);
>  	if (!mtk_crtc->enabled)
> @@ -398,6 +407,11 @@ static void mtk_drm_crtc_atomic_disable(struct drm_crtc *crtc,
>  	mtk_crtc_ddp_hw_fini(mtk_crtc);
>  
>  	mtk_crtc->enabled = false;
> +
> +	ret = pm_runtime_put(comp->dev);
> +	if (ret < 0)
> +		DRM_DEV_ERROR(comp->dev, "Failed to disable power domain: %d\n",
> +			      ret);
>  }
>  
>  static void mtk_drm_crtc_atomic_begin(struct drm_crtc *crtc,
> diff --git a/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c b/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c
> index 7dc8496..c45e1f0 100644
> --- a/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c
> +++ b/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c
> @@ -256,6 +256,8 @@ int mtk_ddp_comp_init(struct device *dev, struct device_node *node,
>  		      struct mtk_ddp_comp *comp, enum mtk_ddp_comp_id comp_id,
>  		      const struct mtk_ddp_comp_funcs *funcs)
>  {
> +	struct platform_device *comp_pdev;
> +
>  	if (comp_id < 0 || comp_id >= DDP_COMPONENT_ID_MAX)
>  		return -EINVAL;
>  
> @@ -282,6 +284,13 @@ int mtk_ddp_comp_init(struct device *dev, struct device_node *node,
>  	if (IS_ERR(comp->clk))
>  		return PTR_ERR(comp->clk);
>  
> +	comp_pdev = of_find_device_by_node(node);
> +	if (!comp_pdev) {
> +		dev_err(dev, "Waiting for device %s\n", node->full_name);
> +		return -EPROBE_DEFER;
> +	}
> +	comp->dev = &comp_pdev->dev;

This should be

	comp->dev = dev;

Regards,
CK

> +
>  	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 108de60..d1838a8 100644
> --- a/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.h
> +++ b/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.h
> @@ -83,6 +83,7 @@ struct mtk_ddp_comp {
>  	struct clk *clk;
>  	void __iomem *regs;
>  	int irq;
> +	struct device *dev;
>  	enum mtk_ddp_comp_id id;
>  	const struct mtk_ddp_comp_funcs *funcs;
>  };

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