Has anybody had any success making CMSIS-DSP work with the Portenta H7?
Are we talking the M4 or M7 core of that thing?
Either core would work for my application. Mostly I am just looking for a successful example.
Assuming you are using the Portenta with framework = arduino, then arm_math.h functions not included in core · Issue #7 · arduino/ArduinoCore-mbed · GitHub applies to you. That is: the Arduino core (which is based on mbed-os) does not include CMSIS-DSP.
This however just means that you need to download the CMSIS-DSP Arduino library (just an Arduino-friendly repackaging of CMSIS5-DSP). I have no problems when using this for the Portenta M7 core. See e.g. GitHub - maxgerhardt/portenta-m7-arduino-dsp-example.
The procedure for other frameworks is the same: Just add CMSIS-DSP in source format, or add just the headers and link in a precompiled library for it (build_flags + old CMSIS lib or build latest yourself).