diff mbox series

[v2,1/4] arm64: dts: qcom: msm8976: Make blsp_dma controlled-remotely

Message ID 20250615-bqx5plus-v2-1-72b45c84237d@apitzsch.eu
State Superseded
Headers show
Series arm64: dts: qcom: msm8976-longcheer-l9360: Add initial device tree | expand

Commit Message

André Apitzsch via B4 Relay June 15, 2025, 8:35 p.m. UTC 
From: André Apitzsch <git@apitzsch.eu>

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 and qcom,sps-dma@7ac4000 [1] so adding
"qcom,controlled-remotely" upstream matches the behavior of the
downstream/vendor kernel.

Adding this fixes booting Longcheer L9360.

[1]: https://git.codelinaro.org/clo/la/kernel/msm-3.10/-/blob/LA.BR.1.3.7.c26/arch/arm/boot/dts/qcom/msm8976.dtsi#L1149-1163

Fixes: 0484d3ce0902 ("arm64: dts: qcom: Add DTS for MSM8976 and MSM8956 SoCs")
Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Signed-off-by: André Apitzsch <git@apitzsch.eu>
---
 arch/arm64/boot/dts/qcom/msm8976.dtsi | 2 ++
 1 file changed, 2 insertions(+)
diff mbox series

Patch

diff --git a/arch/arm64/boot/dts/qcom/msm8976.dtsi b/arch/arm64/boot/dts/qcom/msm8976.dtsi
index e2ac2fd6882fcf47e846a92d45e0fcb9beba633a..2a30246384700dac2ec868c6f371248cfcc643fc 100644
--- a/arch/arm64/boot/dts/qcom/msm8976.dtsi
+++ b/arch/arm64/boot/dts/qcom/msm8976.dtsi
@@ -1331,6 +1331,7 @@  blsp1_dma: dma-controller@7884000 {
 			clock-names = "bam_clk";
 			#dma-cells = <1>;
 			qcom,ee = <0>;
+			qcom,controlled-remotely;
 		};
 
 		blsp1_uart1: serial@78af000 {
@@ -1451,6 +1452,7 @@  blsp2_dma: dma-controller@7ac4000 {
 			clock-names = "bam_clk";
 			#dma-cells = <1>;
 			qcom,ee = <0>;
+			qcom,controlled-remotely;
 		};
 
 		blsp2_uart2: serial@7af0000 {