[PATCH 2/2] riscv: dts: sophgo: Add dma-coherent to SG2042 PCIe controllers

From: Han Gao

Date: Tue Mar 31 2026 - 13:21:15 EST


SG2042's PCIe root complexes are cache-coherent with the CPU. Mark all
four PCIe controller nodes (pcie_rc0 through pcie_rc3) as dma-coherent
so the kernel uses coherent DMA mappings instead of non-coherent bounce
buffering.

Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Han Gao <gaohan@xxxxxxxxxxx>
---
arch/riscv/boot/dts/sophgo/sg2042.dtsi | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/arch/riscv/boot/dts/sophgo/sg2042.dtsi b/arch/riscv/boot/dts/sophgo/sg2042.dtsi
index 9fddf3f0b3b9..3af770549742 100644
--- a/arch/riscv/boot/dts/sophgo/sg2042.dtsi
+++ b/arch/riscv/boot/dts/sophgo/sg2042.dtsi
@@ -417,6 +417,7 @@ pcie_rc0: pcie@7060000000 {
vendor-id = <0x1f1c>;
device-id = <0x2042>;
cdns,no-bar-match-nbits = <48>;
+ dma-coherent;
msi-parent = <&msi>;
status = "disabled";
};
@@ -439,6 +440,7 @@ pcie_rc1: pcie@7060800000 {
vendor-id = <0x1f1c>;
device-id = <0x2042>;
cdns,no-bar-match-nbits = <48>;
+ dma-coherent;
msi-parent = <&msi>;
status = "disabled";
};
@@ -461,6 +463,7 @@ pcie_rc2: pcie@7062000000 {
vendor-id = <0x1f1c>;
device-id = <0x2042>;
cdns,no-bar-match-nbits = <48>;
+ dma-coherent;
msi-parent = <&msi>;
status = "disabled";
};
@@ -483,6 +486,7 @@ pcie_rc3: pcie@7062800000 {
vendor-id = <0x1f1c>;
device-id = <0x2042>;
cdns,no-bar-match-nbits = <48>;
+ dma-coherent;
msi-parent = <&msi>;
status = "disabled";
};
--
2.47.3