Re: [PATCH v3 6/7] arm64: dts: r8a7795: Add missing properties to CA57 L2 cache node

[Sudeep Holla <sudeep.holla@arm.com>]

On 16/02/16 06:40, Dirk Behme wrote:
> On 15.02.2016 21:38, Geert Uytterhoeven wrote:
>> Add the missing "cache-unified" and "cache-level" properties to the
>> Cortex-A57 cache-controller node.
>>
>> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
>> ---
>> v3:
>>    - Remaining part of "[PATCH v2 6/6] arm64: renesas: r8a7795: Add L2
>>      cache-controller nodes", after dropping the "arm,data-latency" and
>>      "arm,tag-latency" properties.
>> ---
>>   arch/arm64/boot/dts/renesas/r8a7795.dtsi | 2 ++
>>   1 file changed, 2 insertions(+)
>>
>> diff --git a/arch/arm64/boot/dts/renesas/r8a7795.dtsi
>> b/arch/arm64/boot/dts/renesas/r8a7795.dtsi
>> index b5e46e4ff72ad003..c07f4e83b988ba42 100644
>> --- a/arch/arm64/boot/dts/renesas/r8a7795.dtsi
>> +++ b/arch/arm64/boot/dts/renesas/r8a7795.dtsi
>> @@ -68,6 +68,8 @@
>>
>>       L2_CA57: cache-controller@0 {
>>           compatible = "cache";
>> +        cache-unified;
>> +        cache-level = <2>;
>
>
> As this is completely unused on ARMv8 I don't think that we want to have
> these unused entries in the DT.
>
> Sudeep: What do you think?
>

I am fine with that, I don't see any issue having them as they are
static values and highly unlikely to change and hence no threat to
backward compatibility.

The main concern I had with latency values is that it's currently not
used anywhere but if we decide to use say in secure software, having the
untested/early values in DT might cause compatibility issues in future
as they were added much before the actual understanding of it's usage.
So I prefer to defer them until then.

-- 
Regards,
Sudeep