Hi, I am trying to set up SPI communication with 2 ADMV8818s, sharing a SPI bus with an AD9082, controlled with a ZCU102 and using ADI's libiio software framework. I have already been successful in controlling a similar setup (only difference was a single ADMV8818 instead of 2). But now the SPI probe for the ADMV8818s keeps failing with an Invalid Chip ID (error -22). Previously my SFL pin on the ADMV8818 was connected to the FPGA through the FMC connector but not actively driven. Right now the SFL pin for both ADMV8818s is connected to a No Connect pin on the FMC connector. I measure a low voltage at the SFL pin on the ADMV8818, but I was wondering if leaving it floating on the FMC connector may be causing the SPI pins to become inactive? Or is there any other debug step I could take to figure out why I am unable to set up SPI communication even though I was able to do it before with the same drivers, device tree nodes etc?