[alsa-devel] [PATCH]Support MCP89 and GT21x hdmi audio

Wei Ni wni at nvidia.com
Wed Mar 3 04:28:26 CET 2010

Hi, Takashi
I still have a question about AZX_MAX_CODECS.
In azx_command_addr() and azx_response_addr(), they use AZX_MAX_CODECS like
If (addr >= AZX_MAX_CODECS) {
    addr = 0;
The azx_max_codes[] could not be used in these functions.
How could we do in these functions?


-----Original Message-----
From: Takashi Iwai [mailto:tiwai at suse.de] 
Sent: Tuesday, March 02, 2010 5:55 PM
To: Wei Ni
Cc: 'Pavel Hofman'; 'alsa-devel'; 'linux-kernel'; 'akpm'
Subject: Re: [alsa-devel] [PATCH]Support MCP89 and GT21x hdmi audio

At Tue, 2 Mar 2010 17:43:28 +0800,
Wei Ni wrote:
> Hi, Takashi
> 1. About AZX_MAX_CODECS, on our new chipset, the codec_mask=0x31, it means
> the codec connect on the slot0, slot4, slot5, and on some GT2xx, the codec
> will connect to slot6 or slot7, although these chip at most have 4 codecs.
> So I change the AZX_MAX_CODECS to 8 directly.
> In hda_intel.c, the azx_command_addr(), azx_response_addr(), and
> azx_codec_create() use the AZX_MAX_CODECS, if it set as 4, the driver will
> not detect the codecs which connect to slot4~7.

Yeah, I understand it.  But, as mentioned, changing this to *all*
controller chips is dangerous.
We have already a quirk for controller chips to set max codecs depending
on the chip model.  Right now, only teradici chip sets to 1.

So, add "#define AZX_DEFAULT_CODECS 4", and use this value unless
azx_max_codecs[] is defined.  And, for the new controller chip
supporting more than 4, it can has 8 in azx_max_codecs[].

Is it feasible?

> 2. yes, it's better to merge the hdmi common codes.
> 3. About ELD, yes, we need to change the Makefile and Kconfig as well.
> Could you help me to change it.

In sound/pci/hda/Makefile, hda_eld.c is built into snd-hda-codec-intelhdmi
by the following rule:

snd-hda-codec-intelhdmi-objs :=	patch_intelhdmi.o hda_eld.o

Since now hda_eld.c is used in two modules, this has to be in the common
place, such as snd-hda-codec.  For this, uncomment the line:

# snd-hda-codec-$(CONFIG_SND_HDA_ELD) += hda_eld.o

and remove hda_eld.o from snd-hda-codec-intelhdmi-objs line.

For Kconfig, right now we have the definition

config SND_HDA_ELD
	def_bool y

Change depends on like


This can be done via "select" instead.  But, we'd merge all hdmi codes
later, so which way to choose is no big matter.


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