linux-kernel - [PATCH 8/8] arm64: dts: qcom: msm8916-pm8916: Mark always-on regulators

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Wed, 17 May 2023 20:48:47 +0200
From:   Stephan Gerhold <stephan@...hold.net>
To:     Bjorn Andersson <andersson@...nel.org>
Cc:     Andy Gross <agross@...nel.org>,
        Konrad Dybcio <konrad.dybcio@...aro.org>,
        Srinivas Kandagatla <srinivas.kandagatla@...aro.org>,
        linux-arm-msm@...r.kernel.org, devicetree@...r.kernel.org,
        linux-kernel@...r.kernel.org, phone-devel@...r.kernel.org,
        ~postmarketos/upstreaming@...ts.sr.ht,
        Stephan Gerhold <stephan@...hold.net>
Subject: [PATCH 8/8] arm64: dts: qcom: msm8916-pm8916: Mark always-on
 regulators

Some of the regulators must be always-on to ensure correct operation of
the system, e.g. PM8916 L2 for the LPDDR RAM, L5 for most digital I/O
and L7 for the CPU PLL (strictly speaking the CPU PLL might only need
an active-only vote but this is not supported for regulators in
mainline currently).

The RPM firmware seems to enforce that internally, these supplies stay
on even if we vote for them to power off (and there is no other
processor running). This means it's pointless to keep sending
enable/disable requests because they will just be ignored.
Also, drivers are much more likely to get a wrong impression of the
regulator status, because regulator_is_enabled() will return false when
there are no users, even though the regulator is always on.

Describe this properly by marking the regulators as always-on.

Signed-off-by: Stephan Gerhold <stephan@...hold.net>
---
 arch/arm64/boot/dts/qcom/apq8016-sbc.dts     | 5 -----
 arch/arm64/boot/dts/qcom/msm8916-pm8916.dtsi | 5 +++++
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/arch/arm64/boot/dts/qcom/apq8016-sbc.dts b/arch/arm64/boot/dts/qcom/apq8016-sbc.dts
index ab8dfd858025..1c5d55854893 100644
--- a/arch/arm64/boot/dts/qcom/apq8016-sbc.dts
+++ b/arch/arm64/boot/dts/qcom/apq8016-sbc.dts
@@ -358,11 +358,6 @@ pm8916_l17: l17 {
 	};
 };
 
-&pm8916_s4 {
-	regulator-always-on;
-	regulator-boot-on;
-};
-
 &sdhc_1 {
 	status = "okay";
 
diff --git a/arch/arm64/boot/dts/qcom/msm8916-pm8916.dtsi b/arch/arm64/boot/dts/qcom/msm8916-pm8916.dtsi
index b38eecbd6253..64d7228bee07 100644
--- a/arch/arm64/boot/dts/qcom/msm8916-pm8916.dtsi
+++ b/arch/arm64/boot/dts/qcom/msm8916-pm8916.dtsi
@@ -72,11 +72,13 @@ pm8916_rpm_regulators: regulators {
 		pm8916_s3: s3 {
 			regulator-min-microvolt = <1250000>;
 			regulator-max-microvolt = <1350000>;
+			regulator-always-on; /* Needed for L2 */
 		};
 
 		pm8916_s4: s4 {
 			regulator-min-microvolt = <1850000>;
 			regulator-max-microvolt = <2150000>;
+			regulator-always-on; /* Needed for L5/L7 */
 		};
 
 		/*
@@ -93,6 +95,7 @@ pm8916_s4: s4 {
 		pm8916_l2: l2 {
 			regulator-min-microvolt = <1200000>;
 			regulator-max-microvolt = <1200000>;
+			regulator-always-on; /* Needed for LPDDR RAM */
 		};
 
 		/* pm8916_l3 is managed by rpmpd (MSM8916_VDDMX) */
@@ -102,6 +105,7 @@ pm8916_l2: l2 {
 		pm8916_l5: l5 {
 			regulator-min-microvolt = <1800000>;
 			regulator-max-microvolt = <1800000>;
+			regulator-always-on; /* Needed for most digital I/O */
 		};
 
 		pm8916_l6: l6 {
@@ -112,6 +116,7 @@ pm8916_l6: l6 {
 		pm8916_l7: l7 {
 			regulator-min-microvolt = <1800000>;
 			regulator-max-microvolt = <1800000>;
+			regulator-always-on; /* Needed for CPU PLL */
 		};
 
 		pm8916_l8: l8 {

-- 
2.40.1