I'm marking this as invalid, because I have traced the source of the problem to scripts that Ubuntu was using to shutdown alsa and bring it back up during suspend resume sequence. After removing sound related scripts from the suspend / resume cycle sound works normally.
** Changed in: alsa-utils (Ubuntu) Status: New => Invalid -- Amixer mutes, but cannot unmute sound https://bugs.launchpad.net/bugs/192669 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs