UART4 is used as CM7 coprocessor debug UART and may not be accessible from
Linux in case it is protected by RDC. The RDC protection is set up by the
platform firmware. UART4 is not used on this platform by Linux. Disable
UART4 by default to prevent boot hangs, which occur when the RDC protection
is in place.
Fixes: 562d222f23f0 ("arm64: dts: imx8mp: Add support for Data Modul i.MX8M Plus eDM SBC")
Signed-off-by: Marek Vasut <marex@xxxxxxx>
---
Cc: Conor Dooley <conor+dt@xxxxxxxxxx>
Cc: Fabio Estevam <festevam@xxxxxxxxx>
Cc: Krzysztof Kozlowski <krzysztof.kozlowski+dt@xxxxxxxxxx>
Cc: NXP Linux Team <linux-imx@xxxxxxx>
Cc: Pengutronix Kernel Team <kernel@xxxxxxxxxxxxxx>
Cc: Rob Herring <robh+dt@xxxxxxxxxx>
Cc: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx>
Cc: Shawn Guo <shawnguo@xxxxxxxxxx>
Cc: devicetree@xxxxxxxxxxxxxxx
Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
---
arch/arm64/boot/dts/freescale/imx8mp-data-modul-edm-sbc.dts | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/arm64/boot/dts/freescale/imx8mp-data-modul-edm-sbc.dts b/arch/arm64/boot/dts/freescale/imx8mp-data-modul-edm-sbc.dts
index 34e9aecc403bd..88e1b76d7d75f 100644
--- a/arch/arm64/boot/dts/freescale/imx8mp-data-modul-edm-sbc.dts
+++ b/arch/arm64/boot/dts/freescale/imx8mp-data-modul-edm-sbc.dts
@@ -491,7 +491,7 @@ &uart3 { /* A53 Debug */
&uart4 {
pinctrl-names = "default";
pinctrl-0 = <&pinctrl_uart4>;
- status = "okay";
+ status = "disabled";
};
&usb3_phy0 {
--
2.43.0
