K 10
svn:author
V 8
hselasky
K 8
svn:date
V 27
2020-04-13T16:28:15.778517Z
K 7
svn:log
V 461
MFC r359355:
Improve USB audio mixer support for USB audio class 1 and 2.
- make sure volume controls are correctly mapped to "pcm" and "rec" depending
  on how they deliver audio to the USB host.
- make sure there are no duplicate record selections.
- remove internal only mixer class type.
- don't add software volume controls for recording only.
- some minor mixer code cleanup.

Tested by:	Horse Ma <Shichun.Ma@dell.com>
Sponsored by:	Mellanox Technologies

END