[LAD] Linux Support for Focusrite Scarlett 18i20 2nd Generation

I am trying to make a Focusrite Scarlett 18i20 (2nd Generation) work as a USB audio capture device with Linux. Using the most current Linux kernel without change (v4.12-rc6), Mic inputs 1 and 2 are successfully captured. However, no other inputs are heard. The Scarlett device also presents a very limited set of ALSA controls. exxothermic@exxothermic-BFC:~$ lsusb Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub Bus 001 Device 002: ID 1235:8201 Focusrite-Novation Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub exxothermic@exxothermic-BFC:~$ amixer -c 1 contents numid=3,iface=MIXER,name='ADAT Validity' ; type=BOOLEAN,access=rw------,values=1 : values=on numid=4,iface=MIXER,name='Clock Source' ; type=ENUMERATED,access=rw------,values=1,items=3 ; Item #0 'Internal' ; Item #1 'S/PDIF' ; Item #2 'ADAT' : values=0 numid=1,iface=MIXER,name='Internal Validity' ; type=BOOLEAN,access=rw------,values=1 : values=on numid=2,iface=MIXER,name='S/PDIF Validity' ; type=BOOLEAN,access=rw------,values=1 : values=on I modified sound/usb driver files mixer_quirks.c and mixer_scarlett.c to treat the Scarlett 2nd generation device the same way it handles the Scarlett 1st generation 0x1235:0x800c 1st Generation 0x1235:0x8201 2nd Generation When checking with amixer, 228 controls are now listed, along with errors that prevent alsamixer from being used. I have no information about how to properly configure these controls. I am interested in any pointer to or information about how to configure and use this Scarlett 2nd Generation device. Thank you, Lloyd Dickman lloyd(a)audioeverywhere.com