[Bug 1921452] Re: [SRU] alsa-lib: conf: USB - add "Cmedia Audio" to USB-Audio.pcm.iec958_device
Launchpad Bug Tracker
1921452 at bugs.launchpad.net
Thu Apr 1 23:14:27 UTC 2021
This bug was fixed in the package alsa-lib - 1.2.4-1.1ubuntu2
alsa-lib (1.2.4-1.1ubuntu2) hirsute; urgency=medium
conf: USB - add "Cmedia Audio" to USB-Audio.pcm.iec958_device
https://github.com/alsa-project/alsa-lib/pull/122 (LP: #1921452)
-- Shengyao Xue <shengyao.xue at canonical.com> Fri, 26 Mar 2021 12:03:07
** Changed in: alsa-lib (Ubuntu Hirsute)
Status: Fix Committed => Fix Released
You received this bug notification because you are a member of Ubuntu
Sponsors Team, which is subscribed to the bug report.
[SRU] alsa-lib: conf: USB - add "Cmedia Audio" to USB-
Status in OEM Priority Project:
Status in alsa-lib package in Ubuntu:
Status in alsa-lib source package in Focal:
Status in alsa-lib source package in Groovy:
Status in alsa-lib source package in Hirsute:
On Cmedia Audio, unusable SPDIF can be selected as output from PulseAudio.
Disable IEC958 (SPDIF) through ALSA UCM.
With the UCM applied, `pactl` and audio panel in gnome-control-center no longer have SPDIF option.
[Where problems will occur]
"Cmedia Audio" is the sound card name of this usb audio dongle, and this string is got from usb string descriptor, that is to say the "Cmedia Audio" is hard-coded in the firmware of that usb dongle.
Not all Cmedia usb audio dongle use "Cmedia Audio", most of the dongles don't set string descriptor, then the audio driver sets a generic name "USB Audio Device" for them, if a dongle has string descriptor, it may have different string like "C-Media USB Headphone Set", and all dongles I met before don't have SPDIF interface.
So If this SRU could introduce regression, it will happen on a Cmedia usb audio dongle which also hard-codes the "Cmedia Audio" in the string descriptor and it has SPDIF interface on it, after this SRU, users couldn't find the SPDIF playback device from the gnome-sound-setting. But this regression chance is very low since it is very rare a cmedia usb audio dongle uses "Cmedia Audio" in the string descriptor and it is very rare a usb audio dongle has SPDIF interface. So far we haven't met such a cmedia usb audio dongle.
To manage notifications about this bug go to:
More information about the Ubuntu-sponsors