linux-kernel - [V5 2/2] arm64: dts: qcom: sc7280-qcard: Configure CTS pin to bias-bus-hold for bluetooth

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]

Message-Id: <1650439639-28428-3-git-send-email-quic_vnivarth@quicinc.com>
Date:   Wed, 20 Apr 2022 12:57:19 +0530
From:   Vijaya Krishna Nivarthi <quic_vnivarth@...cinc.com>
To:     agross@...nel.org, bjorn.andersson@...aro.org, robh+dt@...nel.org,
        krzysztof.kozlowski+dt@...aro.org, linux-arm-msm@...r.kernel.org,
        devicetree@...r.kernel.org, linux-kernel@...r.kernel.org
Cc:     quic_msavaliy@...cinc.com, dianders@...omium.org,
        Vijaya Krishna Nivarthi <quic_vnivarth@...cinc.com>
Subject: [V5 2/2] arm64: dts: qcom: sc7280-qcard: Configure CTS pin to bias-bus-hold for bluetooth

WLAN rail was leaking power during RBSC/sleep even after turning BT off.
Change active and sleep pinctrl configurations to handle same.

Signed-off-by: Vijaya Krishna Nivarthi <quic_vnivarth@...cinc.com>
Reviewed-by: Douglas Anderson <dianders@...omium.org>
---
v5: modify subject to include bluetooth
v4: modify subject of patch to indicate file it is applying to
v3: apply same change to active state and other sc7280*.dts* as well
v2: used bias-bus-hold as per review comments
v1: intial patch used bias-disable for sleep pinctrl in sc7280-idp only
---
 arch/arm64/boot/dts/qcom/sc7280-qcard.dtsi | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/arch/arm64/boot/dts/qcom/sc7280-qcard.dtsi b/arch/arm64/boot/dts/qcom/sc7280-qcard.dtsi
index b833ba1..602ebd4 100644
--- a/arch/arm64/boot/dts/qcom/sc7280-qcard.dtsi
+++ b/arch/arm64/boot/dts/qcom/sc7280-qcard.dtsi
@@ -398,8 +398,11 @@ mos_bt_uart: &uart7 {
 
 /* For mos_bt_uart */
 &qup_uart7_cts {
-	/* Configure a pull-down on CTS to match the pull of the Bluetooth module. */
-	bias-pull-down;
+	/*
+	 * Configure a bias-bus-hold on CTS to lower power usage
+	 * when BT is turned off.
+	 */
+	bias-bus-hold;
 };
 
 /* For mos_bt_uart */
@@ -490,10 +493,10 @@ mos_bt_uart: &uart7 {
 		pins = "gpio28";
 		function = "gpio";
 		/*
-		 * Configure a pull-down on CTS to match the pull of
-		 * the Bluetooth module.
+		 * Configure a bias-bus-hold on CTS to lower power usage
+		 * when BT is turned off.
 		 */
-		bias-pull-down;
+		bias-bus-hold;
 	};
 
 	/* For mos_bt_uart */
-- 
Qualcomm INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, hosted by the Linux Foundation.