Mark,

I performed some testing on the patch to enable Harmony's internal speaker that I recently posted, and found a few strange interactions between the mixer controls.

The relevant controls that appear are in alsamixer are:

Headphone (mute + volume) [default: unmuted, high volume]

Speaker (mute + volume) [default: unmuted, high volume]

Left/Right Speaker Mixer DACL/DACR/Left Bypass/Right Bypass (switch, default muted/off)

Now, if I start playing something, and go enable Right Speaker Mixer DACR, I hear the sound on the speaker. Muting this control turns off the speaker. However, unmuting again doesn't turn the speaker back on.

This exact same behavior is seen for Right Speaker Mixer DACL/Left Bypass. For Left Bypass at least, that's odd, since the ADC path shouldn't be active to Capture anything and bypass it back, and there's no mic attached.

The Right Speaker Right Bypass control works the first and all subsequent times. Perhaps that's something to do with it being the last entry in wm8903.c's right_speaker_mixer[] array?

Finally, the muting either the Headphone and Speaker controls actually affects both the headphone and speaker outputs in all cases, rather than just the output the control is named for.

I briefly started to debug this, and notice that the SND_SOC_DAPM_SPK event function isn't being called at all in the cases where muting doesn't toggle as expected.

I didn't manage to trace the code through the entire ASoc code-base yet, but initial indications were that some register writes for the speaker mixer routing setup weren't sticking - i.e. I'd toggle a control to unmuted, exit alsamixer, restart alsamixer, and the control wouldn't be in the state I'd placed it.

Can you comment on this? I can certainly continue to debug it, but I figured it might be immediately obvious to you what the problem was e.g. if the same thing had happened on other platforms/codecs.

Thanks.