This is a note to let you know that I've just added the patch titled arm64: dts: imx8mp: Disable UART4 by default on Data Modul i.MX8M Plus eDM SBC to the 6.6-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: arm64-dts-imx8mp-disable-uart4-by-default-on-data-mo.patch and it can be found in the queue-6.6 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit e025d7fdc041da4f1e0706889c35aa55916d954e Author: Marek Vasut <marex@xxxxxxx> Date: Wed Dec 20 01:02:42 2023 +0100 arm64: dts: imx8mp: Disable UART4 by default on Data Modul i.MX8M Plus eDM SBC [ Upstream commit f03869698bc3bd6d9d2d9f216b20da08a8c2508a ] 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> Reviewed-by: Fabio Estevam <festevam@xxxxxxxxx> Signed-off-by: Shawn Guo <shawnguo@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> 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 13674dc64be9d..116bf9738a8a4 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 @@ -484,7 +484,7 @@ &uart3 { /* A53 Debug */ &uart4 { pinctrl-names = "default"; pinctrl-0 = <&pinctrl_uart4>; - status = "okay"; + status = "disabled"; }; &usb3_phy0 {