On 18/03/2023 07:07, Jacky Huang wrote: > >> >>> + interrupts = <GIC_PPI 9 (GIC_CPU_MASK_RAW(0x13) | >>> + IRQ_TYPE_LEVEL_HIGH)>; >>> + }; >>> + >>> + uart0:serial@40700000 { >>> + compatible = "nuvoton,ma35d1-uart"; >>> + reg = <0x0 0x40700000 0x0 0x100>; >>> + interrupts = <GIC_SPI 59 IRQ_TYPE_LEVEL_HIGH>; >>> + clocks = <&clk UART0_GATE>; >>> + status = "okay"; >> Why? Drop the line... or convert it to disabled. Otherwise, why every >> SoC has serial0 enabled? Is it used internally? > > > uart0 is on all the way since this SoC booting from the MaskROM boot code, > > load arm-trusted-firmware, load bootloader, and finally load linux kernel. > > uart0 is also the Linux console. Are you sure? Maybe my board has UART0 disconnected. Best regards, Krzysztof