On Sunday 19 April 2015 19:26:58 Gabriele Mazzotta wrote:
Hi,
I've recently found that commit a551d91473 ("ALSA: hda - Use regmap for command verb caches, too") is somehow causing a pop noise on startup when headphones are plugged in, but I couldn't figure out the exact cause. Was this observed on other systems (mine is a Dell XPS13 9333, Realtek ALC3661)? Does anyone have any idea of what the cause might be?
Hi,
I don't know why a551d91473 caused the issue, but I found the real cause of problem.
On init, create_input_ctls() sets the vref of nid 0x19 to 80 (as returned by snd_hda_get_default_vref()), but it should be set to HIZ. This is not so different from the issue addressed by f38663ab5c ("ALSA: hda - Set internal mic as default input source on Dell XPS 13 9333").
I made a patch to prevent this from happening.
Setting the vref is not necessary since alc_update_headset_mode() will take care of it.
Should I maybe add a new flag instead of using suppress_hp_mic_detect?
--- sound/pci/hda/hda_generic.c | 3 ++- sound/pci/hda/patch_realtek.c | 1 + 2 files changed, 3 insertions(+), 1 deletion(-)
diff --git a/sound/pci/hda/hda_generic.c b/sound/pci/hda/hda_generic.c index 3d2597b..adf84ab 100644 --- a/sound/pci/hda/hda_generic.c +++ b/sound/pci/hda/hda_generic.c @@ -3257,7 +3257,8 @@ 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 && + !spec->suppress_hp_mic_detect) val |= snd_hda_get_default_vref(codec, pin); if (pin != spec->hp_mic_pin) set_pin_target(codec, pin, val, false); diff --git a/sound/pci/hda/patch_realtek.c b/sound/pci/hda/patch_realtek.c index 231d0e4..3d854e7 100644 --- a/sound/pci/hda/patch_realtek.c +++ b/sound/pci/hda/patch_realtek.c @@ -4062,6 +4062,7 @@ static void alc_fixup_headset_mode(struct hda_codec *codec,
switch (action) { case HDA_FIXUP_ACT_PRE_PROBE: + spec->gen.suppress_hp_mic_detect = 1; spec->parse_flags |= HDA_PINCFG_HEADSET_MIC | HDA_PINCFG_HEADPHONE_MIC; break; case HDA_FIXUP_ACT_PROBE: