Comment 24 for bug 939161

At Fri, 07 Sep 2012 13:26:35 +0200,
David Henningsson wrote:
>
> On 09/07/2012 12:01 PM, Takashi Iwai wrote:
> > At Fri, 7 Sep 2012 07:25:44 +0200,
> > David Henningsson wrote:
> >>
> >> 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
> >> Signed-off-by: David Henningsson <email address hidden>
> >
> > So this will fix this one case but will break some others certainly.
> > It's a difficult to judge, but more removal is better, so I'll take
> > this.
>
> Ok. Do you have a sense for how many machines that will regress due to
> this patch? If it is common to set all pins to the wrong value, maybe
> its the M31EI that is the exception.

Maybe a few Acer and ASUS ones with old codecs.
Possibly some desktops with unknown mobos might hit, but that's not
what I do care so much for now.

> > But I still wonder why PulseAudio cares the headphone jack state even
> > though this has only one output at all?
>
> When seeing the system as a whole, there can be other outputs on other
> cards - HDMI, USB etc. If somebody e g plugs a USB headset in it will be
> simpler for the user if PulseAudio does not also show the unplugged 3.5
> mm jack.

OK, but masking it out unconditionally isn't always nice. There are
always corner cases...

Takashi