alsactl --init may help. However alsa makes .lock files in /var/lock/alsa and you may find it helpful to delete the lock file first then once card is set run alsactl store. Those lock files sometimes prevent alsa from doing a proper detection and change.
On Sun, 30 Jan 2022, Pankaj Jangid wrote: > "Andrew M.A. Cater" <amaca...@einval.com> writes: > > >> Pankaj Jangid <pan...@codeisgreat.org> writes: > >> > >> > When I boot system afresh, the card is visible in the ?alsamixer? and in > >> > Gnome settings as well. Shown as ?Blue? S/PDIF input and output > >> > devices. But when system wakes up from sleep (suspended), it doesn?t > >> > show the devices. > >> > > > It might be nothing more than the power handling, sleep modes and USB > > enumeration after a laptop goes to sleep. > > > > If you unplug/replug the USB plug which is the external sound card, is > > it magically recognised again? > > Thanks Andy, for the reply. I really appreciate this gesture. > > And I am sorry I wasn?t complete in the original email. I had tried to > unplug and replug. But that also doesn?t list the device in ?alsamixer? > and hence doesn?t work after a suspend/wakeup operation. > > Is there a way to force the scan of USB sound devices manually if that > is not happening automatically? As I had posted earlier that ?lsusb? and > ?cat /proc/asound/cards? do list the device. It is just that ALSA is not > seeing it. > > > Regards ~Pankaj > >