Linux-ARM-MSM Archive on
 help / color / Atom feed
From: Niklas Cassel <>
To: Andy Gross <>
Cc: Niklas Cassel <>,
	Bjorn Andersson <>,
	Rob Herring <>,
	Mark Rutland <>,,,
Subject: [PATCH] arm64: dts: qcom: qcs404-evb: Set vdd_apc regulator in high power mode
Date: Mon, 14 Oct 2019 14:09:20 +0200
Message-ID: <> (raw)

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.

Signed-off-by: Niklas Cassel <>
Suggested-by: Bjorn Andersson <>
 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-name = "vdd_apc";
+		regulator-initial-mode = <1>;
 		regulator-min-microvolt = <1048000>;
 		regulator-max-microvolt = <1384000>;

             reply index

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-10-14 12:09 Niklas Cassel [this message]
2019-10-16  8:14 ` Vinod Koul

Reply instructions:

You may reply publically to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \ \ \ \ \ \ \ \ \ \

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Linux-ARM-MSM Archive on

Archives are clonable:
	git clone --mirror linux-arm-msm/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-arm-msm linux-arm-msm/ \
	public-inbox-index linux-arm-msm

Example config snippet for mirrors

Newsgroup available over NNTP:

AGPL code for this site: git clone