SPI error: full duplex unsupported

Hi all,

I’m using the Barebox bootloader on Beaglebone black and I have a script using the SPI interface (spi0: spi@48030000) to communicate with a hardware chip.

When executing the script I get the following output:

SPI error: full duplex unsupported
wolfTPM2_Init failed 0xffffffea: Unknown

Does the Beaglebone Black not support full duplex SPI or do I need to configure something to enable full duplex?

Simple communication on MOSI works (sending 0x1 0x2 …).

Thanks and kind regards,