Re: [PATCH] ALSA: hda/realtek - Fix headset mic problem for a HP machine with alc671

10 Mar 2022

      On Thu, 10 Mar 2022 14:58:36 +0100,
黄文辉 wrote:
...
Hi  Takashi,
Thank you for your reply.
When booting with plugged headset, the headphone will be muted.
The muted state is the default behavior.  Wouldn't it be unmuted if
you adjust the corresponding mixer element?
Takashi
...
Thanks.
------------------ Original ------------------
From:  "Takashi Iwai"tiwai@suse.de;
Date:  Thu, Mar 10, 2022 09:29 PM
To:  "huangwenhui"huangwenhuia@uniontech.com;
Cc:  "perex"perex@perex.cz; "tiwai"tiwai@suse.com; "jeremy.szu"
jeremy.szu@canonical.com; "hui.wang"hui.wang@canonical.com; "wse"
wse@tuxedocomputers.com; "cam"cam@neo-zeon.de; "kailang"
kailang@realtek.com; "tanureal"tanureal@opensource.cirrus.com; "sami"
sami@loone.fi; "alsa-devel"alsa-devel@alsa-project.org; "linux-kernel"
linux-kernel@vger.kernel.org;
Subject:  Re: [PATCH] ALSA: hda/realtek - Fix headset mic problem for a HP
machine with alc671
On Thu, 10 Mar 2022 14:03:01 +0100,
huangwenhui wrote:
...
On a HP 288 Pro G8, the front Mic could not be detected.
Signed-off-by: huangwenhui huangwenhuia@uniontech.com
Thanks for the patch.  Most of the changes look OK, but one thing I
still don't get:
...

case HDA_FIXUP_ACT_INIT:
alc_write_coef_idx(codec, 0x19, 0xa054);
msleep(80);
snd_hda_codec_write(codec, hp_pin, 0,
AC_VERB_SET_AMP_GAIN_MUTE, AMP_OUT_UNMUTE);

Why this unconditional unmute is required for fixing the mic problem?
Takashi