[alsa-devel] [pulseaudio-discuss] ThinkPad T-510 audio output mute LED non-workingness

[Glenn Golden]

Takashi Iwai <tiwai at suse.de> [2015-04-28 08:06:50 +0200]:
> 
> It's the call:
> 	led_set_func(TPACPI_LED_MUTE, false)
> and this returns an error.  led_set_func is a function pointer to
> tpacpi_led_set:
> 	led_set_func = symbol_request(tpacpi_led_set);
> 
> So the above indicates that the call in thinkpad_acpi.c failed.
> 
> Could you check what value is returned from
> led_set_func(TPACPI_LED_MUTE, false)?
> 
> My wild guess is that it's -ENODEV.
> 

Yep: 

    [   13.379016] sound hdaudioC0D0: XXX hda_fixup_thinkpad_acpi init...
    [   13.392760] sound hdaudioC0D0: XXX ok, this is thinkpad
    [   13.404553] sound hdaudioC0D0: XXX mute LED NOT WORKING!
    [   13.416106] XXX led_set_func(TPACPI_LED_MUTE, false) returned -19
    [   13.427719] sound hdaudioC0D0: XXX ok, mic LED is hooked


Question: To simplify/speed debugging going forward: Is there some
straightforward way to unload/reload all the relevant sound modules as
an alternative to rebooting?  I came across some 'recipes', but none
looked straightforward; lots of conditionality on the particular subset
of modules being patched/debugged, but alas I've not enough knowledge
to guess at exactly what that subset should be for what we're doing here.)
Thx.