[alsa-devel] [PATCH] ALSA: hda - Remove ignore_misc_bit

David Henningsson david.henningsson at canonical.com
Fri Sep 7 14:17:58 CEST 2012

On 09/07/2012 01:59 PM, Takashi Iwai wrote:
> 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 <david.henningsson at canonical.com>
>>> 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.

Hrm, ok. I still don't like the idea of regressing machines...maybe this 
patch needs further research.

>>> 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...

Not sure what corner case you mean here, but if you like, you can 
configure this behaviour in 
causing the jack detection to be ignored if you prefer. And you can 
quirk a specific machine to use another .conf file based on udev rules.

Or is the corner case that ALSA don't give the correct jack detection 
value? If so I prefer it to be fixed in ALSA ;-)

David Henningsson, Canonical Ltd.

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