[alsa-devel] Asus w5f. ALC660-VD codec not detected

[Takashi Iwai]

At Wed, 7 Jan 2009 12:57:57 +0100,
Salvatore Filippone wrote:
> 
> On Wed, Jan 7, 2009 at 12:45 PM, Takashi Iwai <tiwai at suse.de> wrote:
> 
>     At Mon, 29 Dec 2008 19:45:25 +0100,
>     Nigel Henry wrote:
>     >
>     > UPDATE: Salvatore has found a workaround, so that both codecs are
>     detected
>     > correctly. Any help from alsa developers for a permanent fix would be
>     > appreciated. See workaround at bottom of post.
>     >
>     (snip)
>     > <Quoting Salvatore>
>     > Saturday 16:05:58
>     >
>     > Ok,  I finally found a workaround.
>     > According to the thread starting at
>     > http://thread.gmane.org/gmane.linux.alsa.devel/58849
>     > I grabbed the latest source code
>     alsa-driver-1.0.18a.17.g27a32.139.g6e583/
>     > compiled with --with-debug=verbose and got the message
>     > Dec 27 15:13:06 localhost kernel: ALSA
>     > /mnt/travel/ALSA/alsa-driver-1.0.18a.17.g27a32.139.g6e583/pci/hda/../../
>     alsa-kernel/pci/hda/hda_intel.c:779:
>     > codec_mask = 0x2
>     >
>     > I then figure out that the sound device was at codec#0 when it worked,
>     > therefore I changed snd_hda_intel.c by forcing codec_mask
>     >         if (!chip->codec_mask) {
>     >                 chip->codec_mask = azx_readw(chip, STATESTS);
>     >                 chip->codec_mask=0x03;
>     >                 snd_printdd("codec_mask = 0x%x\n", chip->codec_mask);
>     >         }
>     >
>     > And now the sound works correctly.
>     > Of course this opens the question of why azx_readw  does not return a
>     > correct mask;
>    
>     Well, this implies a BIOS bug.  This value is set by BIOS to indicate
>     which codec slot is available.
>    
>     > maybe the developers will be interested and/or will suggest a
>     > fix that is a little more elegant/widely applicable? And why did the
>     base
>     > code work just once, for no clear reason ? (I did not have debug=verbose
>     at
>     > that time, so I don't have detailed messages in the system log).
>    
>     Not sure about this as I didn't track this bug.
>     When did it work once?  Is the device enabled by BIOS properly?
> 
> To summarize: 
> 
>  1. It always did work with FC7.

I guess it worked likely just casually.
The old driver didn't clear the register bit before probing, so it got
uninitialized bits.


Takashi