2019-07-15 12:49:44

by Lukasz Luba

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Subject: [PATCH v1 21/50] ARM: dts: exynos: add OPP into FSYS APB bus in Exynos5420

Add an OPP for FSYS APB which reflects the real possible frequency.
The bus will have a new parent clock which speed has 600MHz, thus
a new possible frequency provided by the clock divider is 150MHz.
According to the documentation max possible frequency for this bus is
200MHz.

Signed-off-by: Lukasz Luba <[email protected]>
---
arch/arm/boot/dts/exynos5420.dtsi | 3 +++
1 file changed, 3 insertions(+)

diff --git a/arch/arm/boot/dts/exynos5420.dtsi b/arch/arm/boot/dts/exynos5420.dtsi
index c7fc4b829b2a..2b36c2f77a10 100644
--- a/arch/arm/boot/dts/exynos5420.dtsi
+++ b/arch/arm/boot/dts/exynos5420.dtsi
@@ -1153,6 +1153,9 @@
opp-hz = /bits/ 64 <100000000>;
};
opp01 {
+ opp-hz = /bits/ 64 <150000000>;
+ };
+ opp02 {
opp-hz = /bits/ 64 <200000000>;
};
};
--
2.17.1


2019-07-17 08:49:40

by Krzysztof Kozlowski

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Subject: Re: [PATCH v1 21/50] ARM: dts: exynos: add OPP into FSYS APB bus in Exynos5420

On Mon, 15 Jul 2019 at 14:44, Lukasz Luba <[email protected]> wrote:
>
> Add an OPP for FSYS APB which reflects the real possible frequency.
> The bus will have a new parent clock which speed has 600MHz, thus
> a new possible frequency provided by the clock divider is 150MHz.
> According to the documentation max possible frequency for this bus is
> 200MHz.

Commit msg is good but title could be improved. Focus in the title
what problem/issue you are solving - add intermediate step in scaling
of FSYS APB?

Best regards,
Krzysztof

2019-07-22 12:36:48

by Lukasz Luba

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Subject: Re: [PATCH v1 21/50] ARM: dts: exynos: add OPP into FSYS APB bus in Exynos5420

Hi Krzysztof,

On 7/17/19 10:48 AM, Krzysztof Kozlowski wrote:
> On Mon, 15 Jul 2019 at 14:44, Lukasz Luba <[email protected]> wrote:
>>
>> Add an OPP for FSYS APB which reflects the real possible frequency.
>> The bus will have a new parent clock which speed has 600MHz, thus
>> a new possible frequency provided by the clock divider is 150MHz.
>> According to the documentation max possible frequency for this bus is
>> 200MHz.
>
> Commit msg is good but title could be improved. Focus in the title
> what problem/issue you are solving - add intermediate step in scaling
> of FSYS APB?
The devfreq governor for this bus device follows the set OPP of the
master device - WCORE bus and sets the OPP with corresponding ID.
Thus, jumping to max frequency 200MHz when the WCORE bus and other
devices are operating in the middle of their min-max speed is not
needed for FSYS APB and this patch adds the intermediate speed step.

Regards,
Lukasz

>
> Best regards,
> Krzysztof
>
>