Well, your firmware does not have SSMS, at all. It is not that
thinkpad-acpi
can't find it due to some change in the acpi core, it simply isn't there
to
be found.
OK, thanks for the detective work, Henrique.
In the interest of documenting what's been learned here (at least by me), what follows is an attempt at a detailed summary/guide to ThinkPad mute key and mute LED behavior when transitioning from 3.18 to 3.19 kernels. Perhaps it may be useful to others who are also head-scratching about this issue, since it involves quite a few moving parts.
It would be great if you could look it over when you have a chance, and correct or bless it as you see fit. I'll also pass it by the PA folks and then post the result to both the original PA ML thread and to the ThinkPad ACPI ML as well (if you want).
============================================================================= For TP models like the T-510 (and others without the SSMS mute LED interface):
- If you want your mute LED to do anything (other than be permanently
off) you have no choice but to set acpi.software_mute=0 at boot time, which reverts to 3.18 behavior. If you do this, then 1-3 below apply. If you don't care whether your mute LED works, then 4-8 further below apply.
The embedded controller (EC) fields mute key events directly, and in response, toggles both the hardware speaker mute gate and the mute LED (if you have one). The kernel is not involved in these actions at all.
"Mute LED on" means, unequivocally, that the hardware mute gate is clamped, i.e. no sound can emit from the speaker, period. The
hardware mute gate has no effect on headphone mute state.
- If you happen to already have the mute key mapped via userspace event to do something with the mixer mute state (e.g. via
amixer/pactl/pacmd, etc.) you should probably disable that mapping in order to avoid unintended conflicts and/or mild insanity.
Do your volume up/down key still work with soft_mute=1 ?
https://bugs.launchpad.net/ubuntu/+source/alsa-driver/+bug/1450947
It seem that Thinkpad X60 's volume up/down key has no effect
Do thinkpad_acpi need to check whether thinkpad support "HAUM" and "SAUM" interface before enable software mute ?