Eh, if you're doing anything in the background on an RPi, timing intensive operations like I2C or SPI get really buggy. Years ago, I had to add a retry function to basic, 3-byte I2C transactions on an RPi, because even something as simple as that was still getting bumped pretty often. These days, I'm more likely to just use a microcontroller for all of those operations, and then use an FTDI cable to let the micocontroller report its results up to the RPi. That's always been easier than setting up something like DMA on an RPi.

Granted, I write microcontroller firmware for a living these days, but I still use RPis and Arduinos for proof-of-concept work because of the simplicity of the toolchains.