Folks,

I have attached 2 SC16IS752 breakout boards to SPI0.

This way I can have 4 UARTs (SC0..3).

All four ports are working, but I have these strange lines during boot:

[   13.239108] spi-bcm2835 20204000.spi: chipselect 1 already in use
[   13.239160] spi_master spi0: spi_device register error /soc/spi@7e204000/spidev@1
[   13.239198] spi_master spi0: Failed to create SPI device for /soc/spi@7e204000/spidev@1

For the two boards I'm using SPI0 on GPIO9,10,11; Board1 uses CE0 (GPIO8), Board2 uses CE1 (GPIO7).

What can cause this error message, and do I have to fear of it?