The SPI flash on SC598 uses different chip select configurations in U-Boot and Linux. They both work but in a confusing way. The flash is physically connected to PA_05/SPI2_SEL1B (hardware SSEL1), so both should use reg = <1>.
https://github.com/analogdevicesinc/linux/blob/adsp-6.12.0-y/arch/arm64/boot/dts/adi/sc598-som-revE.dtsi#L85
https://github.com/analogdevicesinc/u-boot/blob/adi-u-boot-2025.10.y/arch/arm/dts/sc598-som-revE.dtsi#L91
Now both projects use different CS control methods.
Since the flash is connected to hardware SSEL1, Linux side should be fixed.
The SPI flash on SC598 uses different chip select configurations in U-Boot and Linux. They both work but in a confusing way. The flash is physically connected to PA_05/SPI2_SEL1B (hardware SSEL1), so both should use
reg = <1>.https://github.com/analogdevicesinc/linux/blob/adsp-6.12.0-y/arch/arm64/boot/dts/adi/sc598-som-revE.dtsi#L85
https://github.com/analogdevicesinc/u-boot/blob/adi-u-boot-2025.10.y/arch/arm/dts/sc598-som-revE.dtsi#L91
Now both projects use different CS control methods.
Since the flash is connected to hardware SSEL1, Linux side should be fixed.