Hi Takashi,
I think it's time to enable this driver by default because:
- Early versions of this mixer driver did not work on all hardware, so out of caution the driver was disabled by default and had to be explicitly enabled with device_setup=1.
- Since commit 764fa6e686e0 ("ALSA: usb-audio: scarlett2: Fix device hang with ehci-pci") (21/May/2021) no more problems of this nature have been reported.
- Therefore, patch 1 in this series proposes to enable the driver by default, but provide a new device_setup option to disable the driver in case that is needed.
Patch 3 adds support for the Clarett 8Pre USB. This is the first device supported by this driver which is controlled identically to another, so patch 2 first allows sharing the device_info struct between models.
Patch 4 adds the specific product series name (like "Scarlett Gen 2") to various messages so the text is correct without being unwieldy & generic (like "Scarlett Gen 2/3/Clarett USB/Clarett+").
Geoffrey D. Bennett (4): ALSA: scarlett2: Default mixer driver to enabled ALSA: scarlett2: Move USB IDs out from device_info struct ALSA: scarlett2: Add support for Clarett 8Pre USB ALSA: scarlett2: Add correct product series name to messages
sound/usb/mixer_quirks.c | 1 + sound/usb/mixer_scarlett_gen2.c | 148 ++++++++++++++++++-------------- 2 files changed, 83 insertions(+), 66 deletions(-)