Re: [alsa-devel] Pop noise on startup when headphones are plugged in (Dell XPS13 9333)

On Saturday 25 April 2015 13:51:33 Gabriele Mazzotta wrote:

Hi,

I think this the patch here below is simpler than the other I sent. snd_hda_get_default_vref() guesses the vref input pins. We know that some of these are for headphones/headset mics, so we could set the vref to HIZ for these.

Are there systems that would misbehave with this change?

Gabriele

---

diff --git a/sound/pci/hda/hda_generic.c b/sound/pci/hda/hda_generic.c index 3d2597b..081db8b 100644 --- a/sound/pci/hda/hda_generic.c +++ b/sound/pci/hda/hda_generic.c @@ -3257,7 +3257,9 @@ static int create_input_ctls(struct hda_codec *codec) continue;

val = PIN_IN;

• if (cfg->inputs[i].type == AUTO_PIN_MIC)
  

• if (cfg->inputs[i].type == AUTO_PIN_MIC &&
  

•     !cfg->inputs[i].is_headset_mic &&
  

•     !cfg->inputs[i].is_headphone_mic)
  val |= snd_hda_get_default_vref(codec, pin);
  

  if (pin != spec->hp_mic_pin) set_pin_target(codec, pin, val, false);

Sorry, I think I misunderstood the meaning of the two flags and they can't be used like that.