Re: [PATCH] drm: convert DT component matching to component_match_add_release()

[Robin Murphy <robin.murphy@arm.com>]

Hi Russell,

On 03/06/16 08:58, Russell King wrote:
> Convert DT component matching to use component_match_add_release().
>
> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
> ---
>   drivers/gpu/drm/arm/hdlcd_drv.c             | 10 ++++++++--
>   drivers/gpu/drm/armada/armada_drv.c         |  9 +++++++--
>   drivers/gpu/drm/drm_of.c                    | 13 +++++++++----
>   drivers/gpu/drm/msm/msm_drv.c               |  8 +++++++-
>   drivers/gpu/drm/rockchip/rockchip_drm_drv.c | 13 ++++++++++---
>   drivers/gpu/drm/sti/sti_drv.c               |  9 +++++++--
>   drivers/gpu/drm/tilcdc/tilcdc_external.c    |  9 +++++++--
>   7 files changed, 55 insertions(+), 16 deletions(-)
>
> diff --git a/drivers/gpu/drm/arm/hdlcd_drv.c b/drivers/gpu/drm/arm/hdlcd_drv.c
> index b987c63ba8d6..bbde48c4f550 100644
> --- a/drivers/gpu/drm/arm/hdlcd_drv.c
> +++ b/drivers/gpu/drm/arm/hdlcd_drv.c
> @@ -443,11 +443,16 @@ static const struct component_master_ops hdlcd_master_ops = {
>   	.unbind		= hdlcd_drm_unbind,
>   };
>
> -static int compare_dev(struct device *dev, void *data)
> +static int compare_of(struct device *dev, void *data)
>   {
>   	return dev->of_node == data;
>   }
>
> +static void release_of(struct device *dev, void *data)
> +{
> +	of_node_put(data);
> +}

Considering that there's 7 identical copies of this function in this 
patch alone, perhaps there's some mileage in defining it commonly as a 
static __maybe_unused default_release_of() in component.h or drm_of.h 
(and maybe default_compare_of() similarly)?

(Apologies if there's already been some strong argument against that 
which I've not seen, but it seems like a reasonable thing to do.)

Robin.

> +
>   static int hdlcd_probe(struct platform_device *pdev)
>   {
>   	struct device_node *port, *ep;
> @@ -474,7 +479,8 @@ static int hdlcd_probe(struct platform_device *pdev)
>   		return -EAGAIN;
>   	}
>
> -	component_match_add(&pdev->dev, &match, compare_dev, port);
> +	component_match_add_release(&pdev->dev, &match, release_of,
> +				    compare_of, port);
>
>   	return component_master_add_with_match(&pdev->dev, &hdlcd_master_ops,
>   					       match);
> diff --git a/drivers/gpu/drm/armada/armada_drv.c b/drivers/gpu/drm/armada/armada_drv.c
> index 439824a61aa5..6ca2aa36515e 100644
> --- a/drivers/gpu/drm/armada/armada_drv.c
> +++ b/drivers/gpu/drm/armada/armada_drv.c
> @@ -232,6 +232,11 @@ static int compare_of(struct device *dev, void *data)
>   	return dev->of_node == data;
>   }
>
> +static void release_of(struct device *dev, void *data)
> +{
> +	of_node_put(data);
> +}
> +
>   static int compare_dev_name(struct device *dev, void *data)
>   {
>   	const char *name = data;
> @@ -255,8 +260,8 @@ static void armada_add_endpoints(struct device *dev,
>   			continue;
>   		}
>
> -		component_match_add(dev, match, compare_of, remote);
> -		of_node_put(remote);
> +		component_match_add_release(dev, match, release_of,
> +					    compare_of, remote);
>   	}
>   }
>
> diff --git a/drivers/gpu/drm/drm_of.c b/drivers/gpu/drm/drm_of.c
> index bc98bb94264d..5d183479d7d6 100644
> --- a/drivers/gpu/drm/drm_of.c
> +++ b/drivers/gpu/drm/drm_of.c
> @@ -6,6 +6,11 @@
>   #include <drm/drm_crtc.h>
>   #include <drm/drm_of.h>
>
> +static void drm_release_of(struct device *dev, void *data)
> +{
> +	of_node_put(data);
> +}
> +
>   /**
>    * drm_crtc_port_mask - find the mask of a registered CRTC by port OF node
>    * @dev: DRM device
> @@ -101,8 +106,8 @@ int drm_of_component_probe(struct device *dev,
>   			continue;
>   		}
>
> -		component_match_add(dev, &match, compare_of, port);
> -		of_node_put(port);
> +		component_match_add_release(dev, &match, drm_release_of,
> +					    compare_of, port);
>   	}
>
>   	if (i == 0) {
> @@ -140,8 +145,8 @@ int drm_of_component_probe(struct device *dev,
>   				continue;
>   			}
>
> -			component_match_add(dev, &match, compare_of, remote);
> -			of_node_put(remote);
> +			component_match_add_release(dev, &match, drm_release_of,
> +						    compare_of, remote);
>   		}
>   		of_node_put(port);
>   	}
> diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c
> index 9c654092ef78..1f7de47d817e 100644
> --- a/drivers/gpu/drm/msm/msm_drv.c
> +++ b/drivers/gpu/drm/msm/msm_drv.c
> @@ -805,6 +805,11 @@ static int compare_of(struct device *dev, void *data)
>   	return dev->of_node == data;
>   }
>
> +static void release_of(struct device *dev, void *data)
> +{
> +	of_node_put(data);
> +}
> +
>   static int add_components(struct device *dev, struct component_match **matchptr,
>   		const char *name)
>   {
> @@ -818,7 +823,8 @@ static int add_components(struct device *dev, struct component_match **matchptr,
>   		if (!node)
>   			break;
>
> -		component_match_add(dev, matchptr, compare_of, node);
> +		component_match_add_release(dev, matchptr, release_of,
> +					    compare_of, node);
>   	}
>
>   	return 0;
> diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_drv.c b/drivers/gpu/drm/rockchip/rockchip_drm_drv.c
> index a409d1f703cb..f5a68fc031ed 100644
> --- a/drivers/gpu/drm/rockchip/rockchip_drm_drv.c
> +++ b/drivers/gpu/drm/rockchip/rockchip_drm_drv.c
> @@ -421,6 +421,11 @@ static int compare_of(struct device *dev, void *data)
>   	return dev->of_node == np;
>   }
>
> +static void release_of(struct device *dev, void *data)
> +{
> +	of_node_put(data);
> +}
> +
>   static void rockchip_add_endpoints(struct device *dev,
>   				   struct component_match **match,
>   				   struct device_node *port)
> @@ -439,8 +444,8 @@ static void rockchip_add_endpoints(struct device *dev,
>   			continue;
>   		}
>
> -		component_match_add(dev, match, compare_of, remote);
> -		of_node_put(remote);
> +		component_match_add_release(dev, match, release_of,
> +					    compare_of, remote);
>   	}
>   }
>
> @@ -518,7 +523,9 @@ static int rockchip_drm_platform_probe(struct platform_device *pdev)
>   			is_support_iommu = false;
>   		}
>
> -		component_match_add(dev, &match, compare_of, port->parent);
> +		of_node_get(port->parent);
> +		component_match_add_release(dev, &match, release_of,
> +					    compare_of, port->parent);
>   		of_node_put(port);
>   	}
>
> diff --git a/drivers/gpu/drm/sti/sti_drv.c b/drivers/gpu/drm/sti/sti_drv.c
> index 872495e72294..4ee6fa4f1beb 100644
> --- a/drivers/gpu/drm/sti/sti_drv.c
> +++ b/drivers/gpu/drm/sti/sti_drv.c
> @@ -346,6 +346,11 @@ static int compare_of(struct device *dev, void *data)
>   	return dev->of_node == data;
>   }
>
> +static void release_of(struct device *dev, void *data)
> +{
> +	of_node_put(data);
> +}
> +
>   static int sti_bind(struct device *dev)
>   {
>   	return drm_platform_init(&sti_driver, to_platform_device(dev));
> @@ -375,8 +380,8 @@ static int sti_platform_probe(struct platform_device *pdev)
>   	child_np = of_get_next_available_child(node, NULL);
>
>   	while (child_np) {
> -		component_match_add(dev, &match, compare_of, child_np);
> -		of_node_put(child_np);
> +		component_match_add_release(dev, &match, release_of,
> +					    compare_of, child_np);
>   		child_np = of_get_next_available_child(node, child_np);
>   	}
>
> diff --git a/drivers/gpu/drm/tilcdc/tilcdc_external.c b/drivers/gpu/drm/tilcdc/tilcdc_external.c
> index 03acb4f99982..7e11b5ecdd4a 100644
> --- a/drivers/gpu/drm/tilcdc/tilcdc_external.c
> +++ b/drivers/gpu/drm/tilcdc/tilcdc_external.c
> @@ -135,6 +135,11 @@ static int dev_match_of(struct device *dev, void *data)
>   	return dev->of_node == data;
>   }
>
> +static void dev_release_of(struct device *dev, void *data)
> +{
> +	of_node_put(data);
> +}
> +
>   int tilcdc_get_external_components(struct device *dev,
>   				   struct component_match **match)
>   {
> @@ -152,8 +157,8 @@ int tilcdc_get_external_components(struct device *dev,
>
>   		dev_dbg(dev, "Subdevice node '%s' found\n", node->name);
>   		if (match)
> -			component_match_add(dev, match, dev_match_of, node);
> -		of_node_put(node);
> +			component_match_add_release(dev, match, dev_release_of,
> +						    dev_match_of, node);
>   		count++;
>   	}
>
>