Re: [PATCH 05/11] of: Ratify of_dma_configure() interface

[Christoph Hellwig <hch@xxxxxxxxxxxxx>]

On Thu, Sep 26, 2019 at 07:24:49PM -0500, Rob Herring wrote:
> -int of_dma_configure(struct device *dev, struct device_node *np, bool force_dma)
> +int of_dma_configure(struct device *dev, struct device_node *parent, bool force_dma)

This creates a > 80 char line.

>  {
>  	u64 dma_addr, paddr, size = 0;
>  	int ret;
>  	bool coherent;
>  	unsigned long offset;
>  	const struct iommu_ops *iommu;
> +	struct device_node *np;
>  	u64 mask;
>  
> +	np = dev->of_node;
> +	if (!np)
> +		np = parent;
> +	if (!np)
> +		return -ENODEV;

I have to say I find the older calling convention simpler to understand.
If we want to enforce the invariant I'd rather do that explicitly:

	if (dev->of_node && np != dev->of_node)
		return -EINVAL;