Recently we tested the headphone playback on 2 LG machines, if we set
the volume to the max value or near to the max value, the sound is too
loud, it could even bring harm to listeners.
A workaround is to decrease the max volume to a reasonable value for
the headphone's amplifier, then the users couldn't set the volume
bigger than that value from the userspace.
The PCIe reset handlers can run at the same time as the
health thread. This can cause the health thread to
stomp on the PCIe reset. Fix this by preventing the
health thread from running while a PCIe reset is happening.
As part of this use timer_shutdown_sync() during reset and
remove to make sure the timer doesn't ever get rearmed.
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.
Also note that this will probably need to be generalised using
machine-specific limits, but a common limit should do for now.
Cc: <email address hidden> # 6.5
Signed-off-by: Johan Hovold <email address hidden>
Link: https://<email address hidden>
Signed-off-by: Mark Brown <email address hidden>
Signed-off-by: Greg Kroah-Hartman <email address hidden>
Signed-off-by: Manuel Diewald <email address hidden>
Signed-off-by: Stefan Bader <email address hidden>
