[PATCH v2] arm64: dts: r8a7795: Add L2 cache-controller nodes

[Geert Uytterhoeven]

Hi Dirk,

On Mon, Feb 8, 2016 at 9:54 AM, Dirk Behme <dirk.behme at de.bosch.com> wrote:
> On 08.02.2016 09:42, Geert Uytterhoeven wrote:
>> On Fri, Feb 5, 2016 at 10:57 AM, Simon Horman <horms at verge.net.au> wrote:
>>> On Wed, Feb 03, 2016 at 06:21:17PM +0100, Dirk Behme wrote:
>>>> On 16.01.2016 15:17, Dirk Behme wrote:
>>>>> From: Geert Uytterhoeven <geert+renesas at glider.be>
>>>>>
>>>>> Add device nodes for the L2 caches, and link the CPU node to its L2
>>>>> cache node.
>>>>>
>>>>> The L2 cache for the Cortex-A57 CPU cores is 2 MiB large (organized as
>>>>> 128 KiB x 16 ways).
>>>>>
>>>>> Signed-off-by: Geert Uytterhoeven <geert+renesas at glider.be>
>>>>> Signed-off-by: Dirk Behme <dirk.behme at gmail.com>
>>>
>>> [snip]
>>>
>>>> Any further comments to this? If not, could this be applied?
>>>
>>> Sorry for the delay.
>>>
>>> This looks good; I have queued it up.
>>>
>>> It should appear in the next (and devel) branches of my renesas tree
>>> soon.
>>> And in linux-next whenever it includes my updated next branch.
>>
>> So you not only dropped the (controversial) timing related properties, but
>> in addition:
>>
>> +               cache-unified;
>> +               cache-level = <2>;
>>
>> At least the "cache-level" property is marked as required in ePAPR.
>> For "cache-unified", the wording is not that strict in ePAPR, but that
>> property
>> depends on being a unified cache in the first place.
>>
>> So I think these two properties should be re-added.
>
> If I remember correctly, first, these entries are not used at all on ARMv8.
> And second, I think it was mentioned that we therefore want to drop them:
>
> http://lists.infradead.org/pipermail/linux-arm-kernel/2015-December/394936.html
>
> https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/Documentation/devicetree/bindings/arm/l2c2x0.txt?id=0bed4b7aa02c06e05121875dc443295d55b9d91d

I believe the discussion was only about the latency properties, which are
documented in the l2c2x0 DT bindings, and deemed to not apply here
(CC Sudeep).
The DT bindings documented in ePAPR are generic, and apply to all hardware,
unless extended or overridden by more-specific DT bindings.

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert at linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds