From: Vinod Koul <vkoul@kernel.org>
To: Niklas Cassel <niklas.cassel@linaro.org>
Cc: Andy Gross <agross@kernel.org>,
Bjorn Andersson <bjorn.andersson@linaro.org>,
Rob Herring <robh+dt@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
linux-arm-msm@vger.kernel.org, devicetree@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] arm64: dts: qcom: qcs404-evb: Set vdd_apc regulator in high power mode
Date: Wed, 16 Oct 2019 13:44:01 +0530 [thread overview]
Message-ID: <20191016081401.GI2654@vkoul-mobl> (raw)
In-Reply-To: <20191014120920.12691-1-niklas.cassel@linaro.org>
On 14-10-19, 14:09, Niklas Cassel wrote:
> vdd_apc is the regulator that supplies the main CPU cluster.
>
> At sudden CPU load changes, we have noticed invalid page faults on
> addresses with all bits shifted, as well as on addresses with individual
> bits flipped.
>
> By putting the vdd_apc regulator in high power mode, the voltage drops
> during sudden load changes will be less severe, and we have not been able
> to reproduce the invalid page faults with the regulator in this mode.
Reviewed-by: Vinod Koul <vkoul@kernel.org>
This seems a good bug fix, maybe CC stable?
>
> Signed-off-by: Niklas Cassel <niklas.cassel@linaro.org>
> Suggested-by: Bjorn Andersson <bjorn.andersson@linaro.org>
> ---
> arch/arm64/boot/dts/qcom/qcs404-evb.dtsi | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/arch/arm64/boot/dts/qcom/qcs404-evb.dtsi b/arch/arm64/boot/dts/qcom/qcs404-evb.dtsi
> index 501a7330dbc8..522d3ef72df5 100644
> --- a/arch/arm64/boot/dts/qcom/qcs404-evb.dtsi
> +++ b/arch/arm64/boot/dts/qcom/qcs404-evb.dtsi
> @@ -73,6 +73,7 @@
> regulator-always-on;
> regulator-boot-on;
> regulator-name = "vdd_apc";
> + regulator-initial-mode = <1>;
> regulator-min-microvolt = <1048000>;
> regulator-max-microvolt = <1384000>;
> };
> --
> 2.21.0
--
~Vinod
prev parent reply other threads:[~2019-10-16 8:14 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-14 12:09 [PATCH] arm64: dts: qcom: qcs404-evb: Set vdd_apc regulator in high power mode Niklas Cassel
2019-10-16 8:14 ` Vinod Koul [this message]
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