Re: [PATCH] of/fdt: fix error checking for earlycon address

From: Peter Hurley
Date: Wed Oct 28 2015 - 10:56:34 EST


On 10/27/2015 04:46 PM, Rob Herring wrote:
> On Fri, Oct 23, 2015 at 8:15 AM, Peter Hurley <peter@xxxxxxxxxxxxxxxxxx> wrote:
>> Hi Masahiro,
>>
>> On 10/23/2015 07:47 AM, Masahiro Yamada wrote:
>>> fdt_translate_address() returns OF_BAD_ADDR on error. It is defined as
>>> a u64 value, so the variable "addr" should be defined as u64 as well.
>>
>> Good catch.
>>
>> I would prefer if fdt_translate_address() returned resource_size_t (which
>> is the proper type for handling addresses as integers) and that type
>> was propagated through early_init_dt_scan_chosen_serial => of_setup_earlycon.
>
> That can be problematic in the DT code. The size of resource_size_t
> can vary on 32-bit as it is based on phys_addr_t which in turn is
> based on CONFIG_LPAE setting. However, the address sizes in DT are
> fixed and may be 64-bit. So we stick with u64 in the DT code.

I think I see your point about fdt_translate_address(); you want it to
mirror of_translate_address(), yes? If so, then I have no objection
to this patch and will mark it reviewed.

But the u64 value from fdt_translate_address() should be preserved
at least to the ioremap()/set_fixmap() in earlycon_map() .
I could roll that change into my earlycon series that moves
fdt_translate_address() into of_setup_earlycon(), thus preserving
the u64 value until it's assigned to a phys_addr_t.

Regards,
Peter Hurley
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