Hi Takashi,
I discovered an internal "standalone" switch on all the Scarlett Gen 2/3 interfaces with internal mixers. After enabling this switch, the interface will act as a standalone mixer (according to its previous configuration) when not connected to a USB host. The interfaces come from the factory with the switch off, and the vendor driver enables it without question. This patch adds a new ALSA control to set the switch on or off.
This is the first configuration item that is common between the Gen 2 and 3 interfaces but with a different offset, so the patch is in two parts. The first patch allows for the same configuration item to have a different offset between Gen 2/3 and the second patch adds the new switch.
Regards, Geoffrey.
Geoffrey D. Bennett (2): ALSA: scarlett2: Split scarlett2_config_items[] into 3 sections ALSA: scarlett2: Add support for the internal "standalone" switch
sound/usb/mixer_scarlett_gen2.c | 171 ++++++++++++++++++++++++++------ 1 file changed, 141 insertions(+), 30 deletions(-)