From 4bbda9421f316efdaef5dbf642e24925ef7de130 Mon Sep 17 00:00:00 2001 From: Stephan Gerhold Date: Mon, 4 Dec 2023 11:21:21 +0100 Subject: [PATCH] arm64: dts: qcom: msm8939: Make blsp_dma controlled-remotely The blsp_dma controller is shared between the different subsystems, which is why it is already initialized by the firmware. We should not reinitialize it from Linux to avoid potential other users of the DMA engine to misbehave. In mainline this can be described using the "qcom,controlled-remotely" property. In the downstream/vendor kernel from Qualcomm there is an opposite "qcom,managed-locally" property. This property is *not* set for the qcom,sps-dma@7884000 [1] so adding "qcom,controlled-remotely" upstream matches the behavior of the downstream/vendor kernel. Adding this seems to fix some weird issues with UART where both input/output becomes garbled with certain obscure firmware versions on some devices. [1]: https://git.codelinaro.org/clo/la/kernel/msm-3.10/-/blob/LA.BR.1.2.9.1-02310-8x16.0/arch/arm/boot/dts/qcom/msm8939-common.dtsi#L866-872 Cc: stable@vger.kernel.org # 6.5 Fixes: 61550c6c156c ("arm64: dts: qcom: Add msm8939 SoC") Signed-off-by: Stephan Gerhold Reviewed-by: Bryan O'Donoghue Link: https://lore.kernel.org/r/20231204-msm8916-blsp-dma-remote-v1-2-3e49c8838c8d@gerhold.net Signed-off-by: Bjorn Andersson --- arch/arm64/boot/dts/qcom/msm8939.dtsi | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/arm64/boot/dts/qcom/msm8939.dtsi b/arch/arm64/boot/dts/qcom/msm8939.dtsi index 4ba115eecfd5..29f6bd9df2eb 100644 --- a/arch/arm64/boot/dts/qcom/msm8939.dtsi +++ b/arch/arm64/boot/dts/qcom/msm8939.dtsi @@ -1761,6 +1761,7 @@ clock-names = "bam_clk"; #dma-cells = <1>; qcom,ee = <0>; + qcom,controlled-remotely; }; blsp_uart1: serial@78af000 {