diff mbox

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

Message ID 1455568715-20880-7-git-send-email-geert+renesas@glider.be (mailing list archive)
State Accepted
Commit a528b4bf1a2ecb756aa65548fd5518fe82fb4648
Delegated to: Simon Horman
Headers show

Commit Message

Geert Uytterhoeven Feb. 15, 2016, 8:38 p.m. UTC
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(+)

Comments

Dirk Behme Feb. 16, 2016, 6:40 a.m. UTC | #1
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?

Best regards

Dirk
Sudeep Holla Feb. 16, 2016, 9:43 a.m. UTC | #2
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.
Dirk Behme Feb. 16, 2016, 9:55 a.m. UTC | #3
On 16.02.2016 10:43, Sudeep Holla wrote:
>
>
> 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.


Fine with me, thanks! :)

With this clarification:

Acked-by: Dirk Behme <dirk.behme@de.bosch.com>


Thanks again and best regards

Dirk
diff mbox

Patch

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>;
 	};
 
 	extal_clk: extal {