On Fri, Jan 19, 2024 at 12:24:18PM +0100, Johan Hovold wrote: > The UCM configuration for the Lenovo ThinkPad X13s has up until now > been setting the speaker PA volume to the minimum -3 dB when enabling > the speakers, but this does not prevent the user from increasing the > volume further. > > Limit the digital gain and PA volumes to a combined -3 dB in the machine > driver to reduce the risk of speaker damage until we have active speaker > protection in place (or higher safe levels have been established). > > Note that the PA volume limit cannot be set lower than 0 dB or > PulseAudio gets confused when the first 16 levels all map to -3 dB. I tracked the down the root cause for this, which appears to be a bug (feature) in pulseaudio that causes it to reject the dB range if the maximum is negative: https://gitlab.freedesktop.org/pulseaudio/pulseaudio/-/merge_requests/447 This happened to work with v3 which limited the PA volume to the single lowest setting, but would similarly break if anyone wants to set a -1.5 dB limit. Johan
