After commit b4b844930f27 ("tty: serial: fsl_lpuart: drop earlycon entry for i.MX8QXP") earlycon support was essentially removed from imx8qm/imx8qxp due to missing compatible. The commit message says "i.MX8QXP lpuart is compatible with i.MX7ULP" so adding a fallback compatible should be fine. With this change early is supported again on imx8qm/imx8qxp. Signed-off-by: Alexander Stein <alexander.stein@xxxxxxxxxxxxxxx> --- I get the following lines in my 5.10 kernel (backported this change): [ 0.000000] earlycon: lpuart32 at MMIO32 0x000000005a060000 (options '') [ 0.000000] printk: bootconsole [lpuart32] enabled arch/arm64/boot/dts/freescale/imx8qm-ss-dma.dtsi | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/arch/arm64/boot/dts/freescale/imx8qm-ss-dma.dtsi b/arch/arm64/boot/dts/freescale/imx8qm-ss-dma.dtsi index bbe5f5ecfb92..3486b99ab6eb 100644 --- a/arch/arm64/boot/dts/freescale/imx8qm-ss-dma.dtsi +++ b/arch/arm64/boot/dts/freescale/imx8qm-ss-dma.dtsi @@ -19,19 +19,19 @@ uart4_lpcg: clock-controller@5a4a0000 { }; &lpuart0 { - compatible = "fsl,imx8qm-lpuart", "fsl,imx8qxp-lpuart"; + compatible = "fsl,imx8qm-lpuart", "fsl,imx8qxp-lpuart", "fsl,imx7ulp-lpuart"; }; &lpuart1 { - compatible = "fsl,imx8qm-lpuart", "fsl,imx8qxp-lpuart"; + compatible = "fsl,imx8qm-lpuart", "fsl,imx8qxp-lpuart", "fsl,imx7ulp-lpuart"; }; &lpuart2 { - compatible = "fsl,imx8qm-lpuart", "fsl,imx8qxp-lpuart"; + compatible = "fsl,imx8qm-lpuart", "fsl,imx8qxp-lpuart", "fsl,imx7ulp-lpuart"; }; &lpuart3 { - compatible = "fsl,imx8qm-lpuart", "fsl,imx8qxp-lpuart"; + compatible = "fsl,imx8qm-lpuart", "fsl,imx8qxp-lpuart", "fsl,imx7ulp-lpuart"; }; &i2c0 { -- 2.25.1