Skip to content

Commit 4bbda94

Browse files
stephan-ghandersson
authored andcommitted
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: 61550c6 ("arm64: dts: qcom: Add msm8939 SoC") 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-v1-2-3e49c8838c8d@gerhold.net Signed-off-by: Bjorn Andersson <andersson@kernel.org>
1 parent 7c45b6d commit 4bbda94

File tree

1 file changed

+1
-0
lines changed

1 file changed

+1
-0
lines changed

arch/arm64/boot/dts/qcom/msm8939.dtsi

Lines changed: 1 addition & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -1761,6 +1761,7 @@
17611761
clock-names = "bam_clk";
17621762
#dma-cells = <1>;
17631763
qcom,ee = <0>;
1764+
qcom,controlled-remotely;
17641765
};
17651766

17661767
blsp_uart1: serial@78af000 {

0 commit comments

Comments
 (0)