Hannu Savolainen | 1 Mar 17:19 2011

Re: Intel atom SCH support


The controller part doesn't require any work. All controllers work
exactly in the same way.

However codecs are different. To make things even worse motherboard
manufacturers have complete freedom to decide which I/O pin they connect
the jacks and other audio inputs and outputs. It is not enough to write
just one mixer driver for each codec. This needs to be done by hand for
every single motherboard (unless there are boards that have the pins
assigned in the same way).

The mixgen.c can be used to create a skeleton of a mixer driver. Then
the result can be fine tuned by using trial and error approach.

1.3.2011 10.59, Sven.BIEBAUT <at> be.thalesgroup.com wrote:
>> -----Original Message-----
>> From: oss-devel-bounces <at> mailman.opensound.com 
>> [mailto:oss-devel-bounces <at> mailman.opensound.com] On Behalf Of 
>> Hannu Savolainen
>> Sent: 28 February, 2011 23:02
>> To: Discussion mailing list for developers of OSS
>> Subject: Re: [oss-devel] Intel atom SCH support
>> Hi,
>> BIOS update cannot fix this kind of problems. Many codecs 
>> just have too many controls that have redundant 
>> functionality. Hand coding is probably the only way to get 
>> the mixer to work properly.
>> Hannu
> Hello, 
> The OSS support for intel SCH hdaudio is very important for the company I
> work for, 
> so we have no problem of doing the handcoding/tuning to get it working and
> give the changes to the community.
> I have a couple of boards here that I can use, so access to hardware is not
> a problem.
> As for the code itself, I've been churning embedded C for over 10 years now,
> so the actual coding is not a problem either.
> However, I will need a few pointers as to the HOW w.r.t. the inside of OSS. 
> For instance, a small explanation about those widgets the mixgen mentions
> and how to interprete and customize an oss codec driver would help.
> Another thing I would like to identify is whether the problems I face now
> are related to the atom chipset hdaudio controller or to the realtek ALC888
> codec which IIRC is allready supported by OSS. I presume it is the former,
> but I'd like to make sure first ...
> Thanks a lot,
> Sven
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