ALSA: usb-audio: SKIP_IFACE_SETUP regression on Focusrite Scarlett 2i2 (1235:8006)

["Geoffrey D. Bennett" <g@b4.vu>]

Hi Takashi,

A user reported distorted/silent audio on 6.19.7 with a Focusrite 1st
Generation Scarlett 2i2 (1235:8006), caused by 38c322068a26 ("ALSA:
usb-audio: Add QUIRK_FLAG_SKIP_IFACE_SETUP").

The Feedback Format (from /proc stream0) changes from 16.16 to 17.15
when SKIP_IFACE_SETUP is enabled. The user confirmed that removing
SKIP_IFACE_SETUP fixes the issue.

This device doesn't have the internal mixer, Air, or Safe modes that
the quirk was designed to protect, so it doesn't benefit from the
skip.

I'm not sure if there's a better fix than explicitly listing all the
devices that I tested?

E.g. replace:

        VENDOR_FLG(0x1235, /* Focusrite Novation */
                   QUIRK_FLAG_SKIP_CLOCK_SELECTOR |
                   QUIRK_FLAG_SKIP_IFACE_SETUP),

with ~23 of these:

        DEVICE_FLG(0x1235, 0x8203, /* Focusrite Scarlett 2nd Gen 6i6 */
                   QUIRK_FLAG_SKIP_CLOCK_SELECTOR |
                   QUIRK_FLAG_SKIP_IFACE_SETUP),

What do you think?

Report: https://github.com/geoffreybennett/linux-fcp/issues/54

Thanks,
Geoffrey.