Power & Source of Big Ideas

I'm trying to get spi working on m4/8.1. I am able to setup the port, but only write one character. After that, all calls to SPI return -1. I can see the single byte appear on the SPI bus. At boot the spi device reports errors: [ 1.015664] rockchip-spi ff1d0000.spi: Failed to request TX DMA channel ...
With prebuilt Android 8.1 on nanopi m4, Bluetooth won't enable. Popup says BT failed continuously.

Do you have any work around?

Thanks
With prebuilt Android 8.1 on nanopi m4, Bluetooth won't enable. Popup says BT failed continuously.

Do you have any work around?

Thanks