linux-kernel - [PATCH v2 1/2] arm64: dts: qcom: qrb2210-rb1: switch I2C2 to i2c-gpio

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: <20240605-rb12-i2c2g-pio-v2-1-946f5d6b6948@linaro.org>
Date: Wed, 05 Jun 2024 11:55:56 +0300
From: Dmitry Baryshkov <dmitry.baryshkov@...aro.org>
To: Bjorn Andersson <andersson@...nel.org>, 
 Konrad Dybcio <konrad.dybcio@...aro.org>, Rob Herring <robh@...nel.org>, 
 Krzysztof Kozlowski <krzk+dt@...nel.org>, 
 Conor Dooley <conor+dt@...nel.org>
Cc: Caleb Connolly <caleb.connolly@...aro.org>, 
 Alexey Klimov <alexey.klimov@...aro.org>, linux-arm-msm@...r.kernel.org, 
 devicetree@...r.kernel.org, linux-kernel@...r.kernel.org, 
 Dmitry Baryshkov <dmitry.baryshkov@...aro.org>, stable@...r.kernel.org
Subject: [PATCH v2 1/2] arm64: dts: qcom: qrb2210-rb1: switch I2C2 to
 i2c-gpio

On the Qualcomm RB1 platform the I2C bus connected to the LT9611UXC
bridge under some circumstances can go into a state when all transfers
timeout. This causes both issues with fetching of EDID and with
updating of the bridge's firmware. While we are debugging the issue,
switch corresponding I2C bus to use i2c-gpio driver. While using
i2c-gpio no communication issues are observed.

This patch is asusmed to be a temporary fix, so it is implemented in a
non-intrusive manner to simply reverting it later.

Fixes: 616eda24edd4 ("arm64: dts: qcom: qrb2210-rb1: Set up HDMI")
Cc: stable@...r.kernel.org
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@...aro.org>
---
 arch/arm64/boot/dts/qcom/qrb2210-rb1.dts | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/boot/dts/qcom/qrb2210-rb1.dts b/arch/arm64/boot/dts/qcom/qrb2210-rb1.dts
index bb5191422660..8c27d52139a1 100644
--- a/arch/arm64/boot/dts/qcom/qrb2210-rb1.dts
+++ b/arch/arm64/boot/dts/qcom/qrb2210-rb1.dts
@@ -59,6 +59,17 @@ hdmi_con: endpoint {
 		};
 	};
 
+	i2c2_gpio: i2c {
+		compatible = "i2c-gpio";
+
+		sda-gpios = <&tlmm 6 GPIO_ACTIVE_HIGH>;
+		scl-gpios = <&tlmm 7 GPIO_ACTIVE_HIGH>;
+		#address-cells = <1>;
+		#size-cells = <0>;
+
+		status = "disabled";
+	};
+
 	leds {
 		compatible = "gpio-leds";
 
@@ -199,7 +210,7 @@ &gpi_dma0 {
 	status = "okay";
 };
 
-&i2c2 {
+&i2c2_gpio {
 	clock-frequency = <400000>;
 	status = "okay";
 

-- 
2.39.2