[U-Boot] [PATCH] fdt: Try to read #address-cells/size-cells from parent

[Michal Simek]

Hi Simon,

On 10.2.2016 13:04, Michal Simek wrote:
> Read #address-cells and #size-cells from parent if they are not present in
> current node.
> 
> Signed-off-by: Michal Simek <michal.simek at xilinx.com>
> ---
> 
> I have code which read information about memory for zynqmp but memory
> node most of the time doesn't contain #address/size-cells which are
> present in parent node.
> That's why let's try to read it from parent.
> 
> Also I think that we shouldn't return 2 if property is not found because
> it has side effect on 32bit systems with #address/size-cells = <1>;
> 
> ---
>  lib/libfdt/fdt_addresses.c | 18 ++++++++++++++----
>  1 file changed, 14 insertions(+), 4 deletions(-)
> 
> diff --git a/lib/libfdt/fdt_addresses.c b/lib/libfdt/fdt_addresses.c
> index 76054d98e5fd..b164d0988079 100644
> --- a/lib/libfdt/fdt_addresses.c
> +++ b/lib/libfdt/fdt_addresses.c
> @@ -19,10 +19,15 @@ int fdt_address_cells(const void *fdt, int nodeoffset)
>  	const fdt32_t *ac;
>  	int val;
>  	int len;
> +	int parent;
>  
>  	ac = fdt_getprop(fdt, nodeoffset, "#address-cells", &len);
> -	if (!ac)
> -		return 2;
> +	if (!ac) {
> +		parent = fdt_parent_offset(fdt, nodeoffset);
> +		ac = fdt_getprop(fdt, parent, "#address-cells", &len);
> +		if (!ac)
> +			return 2;
> +	}
>  
>  	if (len != sizeof(*ac))
>  		return -FDT_ERR_BADNCELLS;
> @@ -39,10 +44,15 @@ int fdt_size_cells(const void *fdt, int nodeoffset)
>  	const fdt32_t *sc;
>  	int val;
>  	int len;
> +	int parent;
>  
>  	sc = fdt_getprop(fdt, nodeoffset, "#size-cells", &len);
> -	if (!sc)
> -		return 2;
> +	if (!sc) {
> +		parent = fdt_parent_offset(fdt, nodeoffset);
> +		sc = fdt_getprop(fdt, parent, "#size-cells", &len);
> +		if (!sc)
> +			return 2;
> +	}
>  
>  	if (len != sizeof(*sc))
>  		return -FDT_ERR_BADNCELLS;
> 

Simon: Any comment?

Thanks,
Michal