Re: [PATCH 5/5] PCI: tegra: Use helper function for_each_child_of_node_scoped()

[Jonathan Cameron <Jonathan.Cameron@Huawei.com>]

On Wed, 28 Aug 2024 15:38:25 +0800
Zhang Zekun <zhangzekun11@huawei.com> wrote:

> for_each_child_of_node_scoped() provides a scope-based cleanup
> functinality to put the device_node automatically, and we don't need to
> call of_node_put() directly.  Let's simplify the code a bit with the use
> of these functions.
> 
> Signed-off-by: Zhang Zekun <zhangzekun11@huawei.com>
This one will heavily benefit from dev_err_probe()
So I'd strongly suggest using that throughout this function.

Jonathan

> ---
>  drivers/pci/controller/pci-tegra.c | 41 ++++++++++--------------------
>  1 file changed, 14 insertions(+), 27 deletions(-)
> 
> diff --git a/drivers/pci/controller/pci-tegra.c b/drivers/pci/controller/pci-tegra.c
> index d7517c3976e7..f1214b3374da 100644
> --- a/drivers/pci/controller/pci-tegra.c
> +++ b/drivers/pci/controller/pci-tegra.c
> @@ -2106,14 +2106,14 @@ static int tegra_pcie_get_regulators(struct tegra_pcie *pcie, u32 lane_mask)
>  static int tegra_pcie_parse_dt(struct tegra_pcie *pcie)
>  {
>  	struct device *dev = pcie->dev;
> -	struct device_node *np = dev->of_node, *port;
> +	struct device_node *np = dev->of_node;
>  	const struct tegra_pcie_soc *soc = pcie->soc;
>  	u32 lanes = 0, mask = 0;
>  	unsigned int lane = 0;
>  	int err;
>  
>  	/* parse root ports */
> -	for_each_child_of_node(np, port) {
> +	for_each_child_of_node_scoped(np, port) {
>  		struct tegra_pcie_port *rp;
>  		unsigned int index;
>  		u32 value;
> @@ -2122,15 +2122,14 @@ static int tegra_pcie_parse_dt(struct tegra_pcie *pcie)
>  		err = of_pci_get_devfn(port);
>  		if (err < 0) {
>  			dev_err(dev, "failed to parse address: %d\n", err);
> -			goto err_node_put;
> +			return err;
>  		}
>  
>  		index = PCI_SLOT(err);
>  
>  		if (index < 1 || index > soc->num_ports) {
>  			dev_err(dev, "invalid port number: %d\n", index);
> -			err = -EINVAL;
> -			goto err_node_put;
> +			return -EINVAL;
>  		}
>  
>  		index--;
> @@ -2139,13 +2138,12 @@ static int tegra_pcie_parse_dt(struct tegra_pcie *pcie)
>  		if (err < 0) {
>  			dev_err(dev, "failed to parse # of lanes: %d\n",
>  				err);
> -			goto err_node_put;
> +			return err;
>  		}
>  
>  		if (value > 16) {
>  			dev_err(dev, "invalid # of lanes: %u\n", value);
> -			err = -EINVAL;
> -			goto err_node_put;
> +			return -EINVAL;
>  		}
>  
>  		lanes |= value << (index << 3);
> @@ -2159,15 +2157,13 @@ static int tegra_pcie_parse_dt(struct tegra_pcie *pcie)
>  		lane += value;
>  
>  		rp = devm_kzalloc(dev, sizeof(*rp), GFP_KERNEL);
> -		if (!rp) {
> -			err = -ENOMEM;
> -			goto err_node_put;
> -		}
> +		if (!rp)
> +			return -ENOMEM;
>  
>  		err = of_address_to_resource(port, 0, &rp->regs);
>  		if (err < 0) {
>  			dev_err(dev, "failed to parse address: %d\n", err);
> -			goto err_node_put;
> +			return err;
>  		}
>  
>  		INIT_LIST_HEAD(&rp->list);
> @@ -2177,16 +2173,12 @@ static int tegra_pcie_parse_dt(struct tegra_pcie *pcie)
>  		rp->np = port;
>  
>  		rp->base = devm_pci_remap_cfg_resource(dev, &rp->regs);
> -		if (IS_ERR(rp->base)) {
> -			err = PTR_ERR(rp->base);
> -			goto err_node_put;
> -		}
> +		if (IS_ERR(rp->base))
> +			return PTR_ERR(rp->base);
>  
>  		label = devm_kasprintf(dev, GFP_KERNEL, "pex-reset-%u", index);
> -		if (!label) {
> -			err = -ENOMEM;
> -			goto err_node_put;
> -		}
> +		if (!label)
> +			return -ENOMEM;
>  
>  		/*
>  		 * Returns -ENOENT if reset-gpios property is not populated
> @@ -2204,8 +2196,7 @@ static int tegra_pcie_parse_dt(struct tegra_pcie *pcie)
>  			} else {
>  				dev_err(dev, "failed to get reset GPIO: %ld\n",
>  					PTR_ERR(rp->reset_gpio));
> -				err = PTR_ERR(rp->reset_gpio);
> -				goto err_node_put;
> +				return PTR_ERR(rp->reset_gpio);
>  			}
>  		}
>  
> @@ -2223,10 +2214,6 @@ static int tegra_pcie_parse_dt(struct tegra_pcie *pcie)
>  		return err;
>  
>  	return 0;
> -
> -err_node_put:
> -	of_node_put(port);
> -	return err;
>  }
>  
>  /*