[Pkg-alsa-devel] Bug#1110637: alsa-ucm-conf: Focusrite Scarlett 18i20 support breaks in alsa-ucm-conf 1.2.14 (shipped with Trixie)

[Agathe Porte]

Control: tag -1 +moreinfo

Hello,

After exploring this issue a bit it seems that there are multiple issues
with the provided configuration for the 18i20 depending on the
generation.

Instead of reverting the whole profile, I think that one fix could be
the following regex fix that makes the profile match the gen1 18i20:
https://github.com/alsa-project/alsa-ucm-conf/commit/40002e48eee529e6d97cd51b488e1b20d594cc47

Can you confirm, if you have a gen1, that this change fixes the issue
and makes the 18i20 gen1 recognized and work? You can probably edit the
file by hand and change the big `C` to a small `c` and check:

diff --git a/ucm2/USB-Audio/USB-Audio.conf b/ucm2/USB-Audio/USB-Audio.conf
index fe2cd46..65facee 100644
--- a/ucm2/USB-Audio/USB-Audio.conf
+++ b/ucm2/USB-Audio/USB-Audio.conf
@@ -345,11 +345,11 @@ If.focusrite-scarlett-18i20 {
        Condition {
                Type RegexMatch
                String "${CardComponents}"
-               # 800C 1st Gen
+               # 800c 1st Gen
                # 8201 2nd Gen
                # 8215 3rd Gen
                # 821d 4th Gen
-               Regex "USB1235:8(00C|2(01|1(5|d)))"
+               Regex "USB1235:8(00c|2(01|1(5|d)))"
        }
        True.Define.ProfileName "Focusrite/Scarlett-18i20"
 }

If you do not have a 18i20 gen1 but something else then this issue
probably needs more investigation… In the meantime you could use the
version in trixie-backports and check if the issue is still present.

Thanks,

Agathe.