Hi, I am using a thinkpad x220 running debian stable and enjoyed until the upgrade to stretch that the mute button worked when waking up from hibernate-ram already before the desktop environment was fully loaded (especially before music players continue playback) and even when the screen was locked.
I.e. i could send the laptop to hibernate with music playing, and if I want the laptop to be silent when I open it, I could still rely on the mute button. Since I moved to stretch the mute button does not function anymore in this way (I have assigned it with xbindkeys, but this doesn't work with a screen lock in place). After a short google search I tried the suggestions from the arch wiki http://www.thinkwiki.org/wiki/Mute_button and tried changing the line GRUB_CMDLINE_LINUX_DEFAULT="quiet" to GRUB_CMDLINE_LINUX_DEFAULT="quiet acpi_osi=!Linux" or GRUB_CMDLINE_LINUX_DEFAULT="quiet acpi_osi=Linux" in /etc/default/grub (and ran update-grub and rebooted) without success though. Assuming I'm not the only thinkpad user, any others around who encountered that problem and have already found a solution? Or tips for how to get the mute button to work hardware-like again? Thanks in advance, Paul