Re: [PATCH 5/5] of/address: restrict 'no-ranges' kludge to powerpc

[Benjamin Herrenschmidt <benh@kernel.crashing.org>]

On Tue, 2010-06-08 at 08:10 -0600, Grant Likely wrote:
> Certain Apple machines don't use the ranges property correctly, but the
> workaround should not be applied on other architectures.  This patch
> disables the workaround for non-powerpc architectures.

I'm half tempted to add it to the quirk list (which should really be
made generic) so I can disable it on more 'modern' powerpc as well.

Cheers,
Ben.

> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
> CC: Stephen Rothwell <sfr@canb.auug.org.au>
> CC: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> CC: linuxppc-dev@lists.ozlabs.org
> CC: devicetree-discuss@lists.ozlabs.org
> ---
>  drivers/of/address.c |   11 ++++++++++-
>  1 files changed, 10 insertions(+), 1 deletions(-)
> 
> diff --git a/drivers/of/address.c b/drivers/of/address.c
> index 0b04137..5c220c3 100644
> --- a/drivers/of/address.c
> +++ b/drivers/of/address.c
> @@ -346,12 +346,21 @@ static int of_translate_one(struct device_node *parent, struct of_bus *bus,
>  	 * a 1:1 translation at that level. It's up to the caller not to try
>  	 * to translate addresses that aren't supposed to be translated in
>  	 * the first place. --BenH.
> +	 *
> +	 * As far as we know, this damage only exists on Apple machines, so
> +	 * This code is only enabled on powerpc. --gcl
>  	 */
>  	ranges = of_get_property(parent, rprop, &rlen);
> +#if !defined(CONFIG_PPC)
> +	if (ranges == NULL) {
> +		pr_err("OF: no ranges; cannot translate\n");
> +		return 1;
> +	}
> +#endif /* !defined(CONFIG_PPC) */
>  	if (ranges == NULL || rlen == 0) {
>  		offset = of_read_number(addr, na);
>  		memset(addr, 0, pna * 4);
> -		pr_debug("OF: no ranges, 1:1 translation\n");
> +		pr_debug("OF: empty ranges; 1:1 translation\n");
>  		goto finish;
>  	}
>