[alsa-devel] [PATCH] hda: Add logic to force HP mixer creation

Takashi Iwai tiwai at suse.de
Tue Feb 17 21:44:47 CET 2009

At Tue, 17 Feb 2009 13:27:12 -0600,
Mario Limonciello wrote:
> Hi Takashi:
> Takashi Iwai wrote:
>     If "Surround" doesn't do anything, why should it be there?
>     And, does "Headphone" change both headphones even with 4 or 6 ch outputs
>     properly?   Doesn't "Headhpone" change any other output volumes?
> I found what the surround mixer is being used for.  If "Mic as Output" is
> turned on, "Surround"  acts as the mixer to control that jack.

Ah, OK, then the mic jack is connected to the surround DAC.
But don't you have Center and LFE?

> The Headphone mixer changes both of the regular headphone jack's volumes. 
> Changing the "Headphone" volume doesn't affect the speaker outputs at all,
> only the two headphone jacks.

And any control of speaker volume?

>     The patch introduces another exception, and now nobody would understand
>     how the channels and outputs and mixers are assigned together.
> Two points:
> 1) I'm not sure this is as much of a problem as you raise.   I don't believe
> many people even know how the channels and mixers are assigned in the first
> place.  I see plenty of support requests for "why doesn't this second
> headphone jack work with headphones".

Exactly this is why I complained.  The current code is already way too
complex and you have no idea how the I/O jacks are connected to which
channel.  Now you add another flag.  That seems to shift the DAC index
by some reason.  And, make the first one as "Headphone" by some 
reason.  But what reason is it exactly?  My inner voice says that
something gets wrong now.  The time to clean up, make things straight
than adding another short-cut.

>  I've never seen one of "I can't hook up
> my 7.1 surround system to my consumer grade laptop and have all of my speakers
> work".

And exactly this is another point why I feel the necessity of
cleanup.  If the feature isn't needed, we should get rid of it.  Or,
implement in a better form.

> These machines come with DisplayPort and HDMI ports which people will
> generally be using for hooking up to their television sets.  I seem to think
> it's not very common to use the analogue jacks to independently hook up pairs
> of speakers assigned to say Front or Surround.
> 2) You are still able to hook up a separate set of speakers to the mic output
> jack and since those are assigned surround have things work as expected.

One more another problem is that this setup thingy isn't described
at all, or pretty hard to guess from the mixer control.  There are
knobs, but you don't know the combination.

>     Hm, I thought I did.  Which patch exactly?
> The patch title was [PATCH] hda: Add STA_DELL_S14 quirk.  Here's the starting
> part of it:
> Add STAC_DELL_S14 quirk for new laptop series. Removed un-needed pins in pin_nids
> for stac92hd83xxx. Also reorganized connection selection code for the respective ports
> per quirk define.

This must be included.  Check commit
in sound git tree.



> ---
>  sound/pci/hda/patch_sigmatel.c |   52 +++++++++++++++++++++++++++-------------
>  1 files changed, 35 insertions(+), 17 deletions(-)
> You responded to the mail saying it was applied, but I seem to not be able to
> find it in current ALSA git.
> Regards
> --
> Mario Limonciello
> Dell | Linux Engineering
> mario_limonciello at dell.com
> [2 OpenPGP digital signature <application/pgp-signature (7bit)>]

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