Re: [Linphone-users] One-Way Audio Issues

[Jim Diamond]

On Tue, Apr  5, 2011 at 16:50 (+0400), Andrew Savchenko wrote:

> Hi,

> On Mon, 4 Apr 2011 20:34:09 -0300 Jim Diamond wrote:
>> If it were only that easy...

>> modinfo does not tell me that there is a 'fujitsu' option for my card.
>> Poking around in
>>      /usr/src/linux-2.6.37.5/Documentation/sound/alsa/HD-Audio-Models.txt
>> I see there are only seven options for my card (ALC269) listed, so I guess
>> with some patience and testing I could find out whether one of the
>> other options works even better.  Mind you, in
>>      /usr/src/linux-2.6.37.5/sound/pci/hda/patch_realtek.c
>> there are 10 models listed, but I guess if I can't specify each one
>> individually it doesn't really matter how many models there are.

> It looks like you misunderstood me.
Not unless I continue to misunderstand you, which, I suppose, is
possible.

> You can build a kernel in a way, that you will have different
> modules for different hda-intel models, not a single one driver.
Yes, but (for example) the snd_hda_codec_realtek module covers many,
many models of sound cards.  So even once someone has decided that the
realtek module is the correct one to compile, they still (might) need
to explicitly tell the kernel which model they are using.

For example, there are (in 2.6.37.5) 53 models of the ALC882 card.
And someone hunting for the correct model for their computer could
quickly eliminate some of them based on brand name (I'd guess), but
there are still a lot of things to try out.

And not all of the names are helpful.  My laptop is a Fujitsu
Lifebook.  So should I use model=lifebook, which would seem like the
obvious choice?  No, I need model=fujitsu.  Duh.  (It seems that
model=laptop-dmic also works, but how many people know what "dmic"
means?)

> This will simplify things a lot since most of this modules will not
> work on the very same hardware.
That's true.  Mind you, discovering that could be very labour intensive.
If a given module loads but doesn't work, you may just need to try
loading it with different options, of which there might be many.

>> However, you are right that if someone wants to dig far enough, they
>> can discover what the options are for their card and try it out.  But
>> I think it is a shortcoming that a user (who might not be as
>> kernel-savvy as you, or at all kernel-savvy) needs to do something
>> like this to figure out how to make his or her sound card work
>> correctly.
> I understand, this may be a tricky way for a common user, but at this
> moment I can't offer another solution.
Nor would I expect you to.  Maybe it is just an issue of the kernel
developers keeping up with all of the different card models so that
(when possible) the module, when initially loading, can do a better
job of picking the correct sub-sub model.  Easy for me to say, since
I'm not writing those drivers.

Or maybe some benevolent person needs to start a wiki which can have
all of this information in one easy-to-find place.  I see the ALSA
project web site has a vendor list, the page for Intel says
        This page was last modified 05:10, 23 December 2007.
Ho hum.

Cheers.
                                Jim