This is a note to let you know that I've just added the patch titled
arm64: dts: qcom: msm8939: Make blsp_dma controlled-remotely
to the 6.6-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
arm64-dts-qcom-msm8939-make-blsp_dma-controlled-remotely.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 4bbda9421f316efdaef5dbf642e24925ef7de130 Mon Sep 17 00:00:00 2001
From: Stephan Gerhold <stephan@xxxxxxxxxxx>
Date: Mon, 4 Dec 2023 11:21:21 +0100
Subject: arm64: dts: qcom: msm8939: Make blsp_dma controlled-remotely
From: Stephan Gerhold <stephan@xxxxxxxxxxx>
commit 4bbda9421f316efdaef5dbf642e24925ef7de130 upstream.
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@xxxxxxxxxxxxxxx # 6.5
Fixes: 61550c6c156c ("arm64: dts: qcom: Add msm8939 SoC")
Signed-off-by: Stephan Gerhold <stephan@xxxxxxxxxxx>
Reviewed-by: Bryan O'Donoghue <bryan.odonoghue@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20231204-msm8916-blsp-dma-remote-v1-2-3e49c8838c8d@xxxxxxxxxxx
Signed-off-by: Bjorn Andersson <andersson@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/arm64/boot/dts/qcom/msm8939.dtsi | 1 +
1 file changed, 1 insertion(+)
--- a/arch/arm64/boot/dts/qcom/msm8939.dtsi
+++ b/arch/arm64/boot/dts/qcom/msm8939.dtsi
@@ -1661,6 +1661,7 @@
clock-names = "bam_clk";
#dma-cells = <1>;
qcom,ee = <0>;
+ qcom,controlled-remotely;
};
blsp_uart1: serial@78af000 {
Patches currently in stable-queue which might be from stephan@xxxxxxxxxxx are
queue-6.6/arm64-dts-qcom-add-missing-vio-supply-for-aw2013.patch
queue-6.6/arm64-dts-qcom-msm8939-make-blsp_dma-controlled-remotely.patch
queue-6.6/arm64-dts-qcom-msm8916-make-blsp_dma-controlled-remotely.patch
