Comment 39 for bug 939161

At Sat, 8 Sep 2012 09:10:14 +0800,
Raymond Yau wrote:
>
> 2012-9-7 下午1:26 於 "David Henningsson" <email address hidden> 寫道：
> >
> > The purpose of this flag is unclear. If the problem is that some machines
> > have broken misc/NO_PRESENCE bits, they should be fixed by pin fixups.
> >
> > In addition, this causes jack detection functionality to be flawed on
> > the M31EI, where there are two jacks without jack detection (which is
> > properly marked as NO_PRESENCE), but due to ignore_misc_bit, these
> > jacks are instead being reported as being present but always unplugged.
> >
> > BugLink: https://bugs.launchpad.net/bugs/939161
>
> do you mean the commit does not fix the bug?
>
> ALSA: hda - add support for Uniwill ECS M31EI notebook
>
> This hardware requires same fixup for the node 0x0f like Asus A6Rp.
> More information: https://bugzilla.redhat.com/show_bug.cgi?id=785417
>
> http://git.kernel.org/?p=linux/kernel/git/tiwai/sound.git;a=commit;h=416846d2b31fc740ed9d5a5ec116964fb43c4358
>
> the real cases are those desktop which does not use hda front audio panel ,
> they just loss the auto mute since there is no jack detect circuit but they
> can still hear sound from the headphone at anytime
>
> do pulseaudio need a phantom port for the front panel headphone and mic
> without jack detection ?

Actually this is one good point.
The jack detection isn't always reliably on such old machines, and
BIOS cannot know, too. That is, it has to be adjusted by user
manually, whether the jack detection is enabled or not.

So far, we solved this by providing "Auto-Mute Mode" mixer switch.
But the jack detection controls don't follow this yet. Maybe we can
set such a jack control as inactive state when the jack detection is
disabled.

(And this reminds me that we can cut off "Phantom" name hack by
 following the same rule -- just set the control inactive when it has
 no real detection. But it still appears in control list.)

Takashi