Re: [PATCH 3/4] ASoC: wm8940: Mute also the speaker output

On Wed, Dec 14, 2022 at 01:37:42PM +0100, Lukasz Majewski wrote:

Without this change the BTL speaker produces some "distortion" noise when test program (speaker-test -t waw) is ended with ctrl+c.

As our design uses speaker outputs to drive BTL speaker, it was necessary to also mute the speaker via the codec internal WM8940_SPKVOL register with setting WM8940_SPKMUTE bit.

Signed-off-by: Lukasz Majewski lukma@denx.de

• spkvol_reg &= ~WM8940_SPKMUTE;
• if (mute) { mute_reg |= 0x40;

• spkvol_reg |= WM8940_SPKMUTE;
  

• }
• ret = snd_soc_component_write(component, WM8940_SPKVOL, spkvol_reg);
• if (ret)

• return ret;
  

This bit is also controlled by the "Speaker Playback Switch" so you probably need some locking between them to stop them clobbering each other.

Thanks, Charles