arm64: dts: qcom: msm8916: 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/msm8916.dtsi#L1466-1472

Cc: stable@vger.kernel.org # 6.5
Fixes: a0e5fb103150 ("arm64: dts: qcom: Add msm8916 BLSP device nodes")
Signed-off-by: Stephan Gerhold <stephan@gerhold.net>
Reviewed-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
Link: https://lore.kernel.org/r/20231204-msm8916-blsp-dma-remote-v1-1-3e49c8838c8d@gerhold.net
Signed-off-by: Bjorn Andersson <andersson@kernel.org>

diff --git a/arch/arm64/boot/dts/qcom/msm8916.dtsi b/arch/arm64/boot/dts/qcom/msm8916.dtsi
index e8a14dd7e7c218c598add79312bc5e13da8ee7ff..7f8327b0dbdb41d0a8baf3a34b0c6d0c97a60b8e 100644 (file)
--- a/arch/arm64/boot/dts/qcom/msm8916.dtsi
+++ b/arch/arm64/boot/dts/qcom/msm8916.dtsi
@@ -2155,6 +2155,7 @@
                        clock-names = "bam_clk";
                        #dma-cells = <1>;
                        qcom,ee = <0>;
+                       qcom,controlled-remotely;
                };
 
                blsp_uart1: serial@78af000 {