[PATCH] arm64: dts: imx8mp: Disable UART4 by default on Data Modul i.MX8M Plus eDM SBC

Marek Vasut marex at denx.de
Tue Dec 19 16:02:42 PST 2023


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 at denx.de>
---
Cc: Conor Dooley <conor+dt at kernel.org>
Cc: Fabio Estevam <festevam at gmail.com>
Cc: Krzysztof Kozlowski <krzysztof.kozlowski+dt at linaro.org>
Cc: NXP Linux Team <linux-imx at nxp.com>
Cc: Pengutronix Kernel Team <kernel at pengutronix.de>
Cc: Rob Herring <robh+dt at kernel.org>
Cc: Sascha Hauer <s.hauer at pengutronix.de>
Cc: Shawn Guo <shawnguo at kernel.org>
Cc: devicetree at vger.kernel.org
Cc: linux-arm-kernel at lists.infradead.org
---
 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




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