[PATCH V3 1/3] arm64: dts: imx8mp-evk: Disable PCIe bus in the default dts

Sherry Sun
2026-03-25T08:30:59Z

Disable the PCIe bus in the default device tree to avoid shared
regulator conflicts between SDIO and PCIe buses. The non-deterministic
probe order between these two buses can break the PCIe initialization
sequence, causing PCIe devices to fail detection intermittently.

On i.MX8MP EVK board, the M.2 connector is physically wired to both
USDHC1 and PCIe0, however the out-of-box module is SDIO IW612 WiFi, so
enable the SDIO WiFi in the default imx8mp-evk.dts.

Add 'm2_usdhc' label to USDHC1 to support device tree overlay for PCIe
modules. Users who need PCIe can use imx8mp-evk-pcie.dtb (added in a
follow-up patch) which applies an overlay to enable PCIe and disable
USDHC1.

Signed-off-by: Sherry Sun <sherry.sun@nxp.com>
---
arch/arm64/boot/dts/freescale/imx8mp-evk.dts | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/boot/dts/freescale/imx8mp-evk.dts b/arch/arm64/boot/dts/freescale/imx8mp-evk.dts
index aedc09937716..315a4e1c5809 100644
--- a/arch/arm64/boot/dts/freescale/imx8mp-evk.dts
+++ b/arch/arm64/boot/dts/freescale/imx8mp-evk.dts
@@ -773,7 +773,7 @@ &pcie0 {
vpcie-supply = <&reg_pcie0>;
vpcie3v3aux-supply = <&reg_pcie0>;
supports-clkreq;
- status = "okay";
+ status = "disabled";
};

&pcie0_ep {
@@ -869,7 +869,7 @@ &uart3 {
status = "okay";
};

-&usdhc1 {
+m2_usdhc: &usdhc1 {
pinctrl-names = "default", "state_100mhz", "state_200mhz";
pinctrl-0 = <&pinctrl_usdhc1>;
pinctrl-1 = <&pinctrl_usdhc1_100mhz>;
--
2.37.1