Can't build on Ubuntu 19.10

[dmt0]

Getting the following output:

buntu@ubuntu:~/snd-microbookii$ make
make -C /lib/modules/5.3.0-18-generic/build M=/home/ubuntu/snd-microbookii modules
make[1]: Entering directory '/usr/src/linux-headers-5.3.0-18-generic'
  CC [M]  /home/ubuntu/snd-microbookii/audio.o
/home/ubuntu/snd-microbookii/audio.c:898:10: error: ‘snd_pcm_lib_mmap_vmalloc’ undeclared here (not in a function); did you mean ‘snd_pcm_lib_mmap_iomem’?
  898 |  .mmap = snd_pcm_lib_mmap_vmalloc,
      |          ^~~~~~~~~~~~~~~~~~~~~~~~
      |          snd_pcm_lib_mmap_iomem
make[2]: *** [scripts/Makefile.build:290: /home/ubuntu/snd-microbookii/audio.o] Error 1
make[1]: *** [Makefile:1653: _module_/home/ubuntu/snd-microbookii] Error 2
make[1]: Leaving directory '/usr/src/linux-headers-5.3.0-18-generic'
make: *** [Makefile:5: all] Error 2

If I make the suggested change, it builds with warnings.
Was able to insmod it, but couldn't test it as it doesn't want to show up in lsusb. Works fine on Windows though.

[Benitoite]

on Debian 4.19.98-1 (2020-01-26) x86_64 GNU/Linux

Successful make with same suggested change and successful dkms kernel integration.

$ lsusb
Bus 002 Device 003: ID 07fd:0004 Mark of the Unicorn 

but when recording a 16bit/44.1kHz track from the MicrobookII: - (hw:2,0) device in Audacity I get this error popup "Error opening sound device. Try changing the audio host, recording device and the project sample rate."
with console output:

Expression 'hostFormat = PaUtil_SelectClosestAvailableFormat( availableFormats, parameters->sampleFormat )' failed in 'src/hostapi/alsa/pa_linux_alsa.c', line: 1786

Also, MicrobookII must be plugged in after boot.

[manuel-rhdt]

Please note that since linux kernel 5.1 the Microbook II is supported without the external kernel module. The patch may thus not be in current distribution kernel yet.

Also note that recording 44.1kHz track does not work with this driver. The driver is currently hard-coded to 96kHz.