linux-kernel - Re: [PATCH] ARM: dts: add 533 MHz step to p4note GPU opp table

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Message-ID: <1b04c8b0-389b-8937-ef2c-47719e771a25@canonical.com>
Date:   Mon, 31 Jan 2022 13:24:36 +0100
From:   Krzysztof Kozlowski <krzysztof.kozlowski@...onical.com>
To:     Martin Jücker <martin.juecker@...il.com>
Cc:     Rob Herring <robh+dt@...nel.org>, devicetree@...r.kernel.org,
        linux-arm-kernel@...ts.infradead.org,
        linux-samsung-soc@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] ARM: dts: add 533 MHz step to p4note GPU opp table

On 31/01/2022 13:15, Martin Jücker wrote:
> On Mon, Jan 31, 2022 at 09:54:00AM +0100, Krzysztof Kozlowski wrote:
>> On 29/01/2022 23:14, Martin Jücker wrote:
>>> The p4note devices support 533 MHz GPU speed, so let's make use of it.
>>>
>>
>> If there is going to be resend, please add prefix "exynos:" in subject.
>> Just like other commits (git log --oneline arch/arm/boot/dts/exynos*).
>>
>>> Signed-off-by: Martin Jücker <martin.juecker@...il.com>
>>> ---
>>>  arch/arm/boot/dts/exynos4412-p4note.dtsi | 7 +++++++
>>>  1 file changed, 7 insertions(+)
>>>
>>> diff --git a/arch/arm/boot/dts/exynos4412-p4note.dtsi b/arch/arm/boot/dts/exynos4412-p4note.dtsi
>>> index 4ae6eb3091c4..d277b2337ae0 100644
>>> --- a/arch/arm/boot/dts/exynos4412-p4note.dtsi
>>> +++ b/arch/arm/boot/dts/exynos4412-p4note.dtsi
>>> @@ -355,6 +355,13 @@ &gpu {
>>>  	status = "okay";
>>>  };
>>>  
>>> +&gpu_opp_table {
>>> +	opp-533000000 {
>>> +		opp-hz = /bits/ 64 <533000000>;
>>> +		opp-microvolt = <1075000>;
>>> +	};
>>> +};
>>
>> This looks like Exynos4412 Prime. Please check also CPU frequencies and
>> if they match, just include exynos4412-prime.dtsi (like Odroid U3).
>>
>>> +
>>>  &hsotg {
>>>  	vusb_a-supply = <&ldo12_reg>;
>>>  	dr_mode = "peripheral";
>>
>>
>> Best regards,
>> Krzysztof
> 
> I just noticed, that I overlooked a condition in the code which
> decreases the step count by one which eliminates the 533 MHz step.
> Please ignore this patch.

Yeah:
	if(samsung_rev() < EXYNOS4412_REV_2_0)
		step_num = MALI_DVFS_STEPS - 1;

Your case, although possible, would be unlikely.

Best regards,
Krzysztof