Tricky alsa kernel 2.6 problem.

raid517 · l33t Joined: 06 Mar 2003 Posts: 946

Hi, I have kernel 2.6-test 5 installed on a Gentoo Linux machine (yeah I know there's a more recent version, but I figured I might as well wait now for an RC release or something, the betas are comming thick and fast). Anyhoo, as you may or may not know, alsa is now included as an official component of the new kernel.

However my problem is I have no analouge sound system to connect to the anolouge outs on my computer system. All I have is an optical digital out connected to a SPDIF connector on my motherboard, leading in turn to a dolby digital 7.1 reciever. But unsurprisingly to some here perhaps, I cannot hear any sound.

I know this settup works in Linux, as the identical same set-up worked in Red Hat without any additional configuration by me at all.

I have enabled alsa in the kernel and disabled OSS support.

the options I have in the kernel are:

krinkle · Posted: Wed Oct 01, 2003 6:37 am Post subject:

Have you ever had this setup working in gentoo before? radhat probably configured something automaticaly w/ alsa. I'm guessing that your problem lies w/ your alsa config, not the kernel. you probably need to work some asound magic. do some searching around for that. I'm not good w/ asound, but it sounds like you need to route some signals or something through that. maybe try running alsamixer and seeing if you can do something useful through there.

Baldzius · Posted: Wed Oct 01, 2003 6:47 am Post subject:

Hi raid517

I see you got new problems

I also have a VT8235 chipset and also have problem with sound using alsa drivers. Don't know nthg about test5 or test6, but from test1 to test4 there were no sound from my computer so i am using OSS drivers.
I think it's related to kernel as have no problem with 2.4.x kernel.

Also check dmesg output, what it is saying about your sound chipset?

raid517 · l33t Joined: 06 Mar 2003 Posts: 946

Thanks very much for the input and reading my question. Unfortunately the answer to your question is no, I have never had this configuration working in gentoo before. But then again, I never really got this far with Gentoo before. Sound is the only remaining hurdle. Let me correct that... I have had sound working on this configuration in the past, but it was purely analouge sound, not digital/SPDIF.

I put this down at the time to the rather old version of alsa that was available on the portage tree, and at that time resolved I would give the 2.6 kernel a go as that had built in alsa support already - and a much more up to date version too.

In any case, as regards Alsa mixer, I have everything turned up full and I still can't hear anything. There isn't a control in alsa mixer that I can see that is specifically for SPDIF output anyway.

Red Hat was cool for this, it took nothing from me to get it to work. However Red Hat was a dependancy nightmare, which made me abandon it.

I am curious about this alsa.config file you refer to? Does alsa have a config file like this? And if so how would I go about enabling it to ouput digital sound only?

All input is appreciated.

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raid517 · l33t Joined: 06 Mar 2003 Posts: 946

Baldzius · Posted: Wed Oct 01, 2003 8:59 am Post subject:

krinkle · Posted: Wed Oct 01, 2003 3:42 pm Post subject:

are you building teh alsa drivers into the kernel or as modules? the sound file to check out is /etc/asound.conf. i don't think gentoo even creates one by default. check out this page on the alsa site. they call it the .asoundrc file. (/etc/asound.conf is global whereas .asoundrc would go in your home dir). I gotta run to school, but wanted to shoot that over to you. and yes, i know it's really confusing =)

raid517 · l33t Joined: 06 Mar 2003 Posts: 946

Thanks for the input. But this is where it gets really confusing as I don't have a file called /etc/asound.conf, or asound anything for that matter.... Also, just to clarify, I opted to include alsa as part of the kernel and not as modules, so that possibly could be why you are seeing that message. I could try including them as modules, but until I learn how to enable digital out-put that isn't much use either.

As for OSS, I can't use it, as as far as I'm aware OSS does not support digital output and that is the only option I have atm. I do not currently have any analogue speakers i could use.

Ahh rats... You know I have asked the cream of the Linux community about this and no one seems to know...

I wonder though, what if I removed alsa support from the 2.6 kernel and just installed alsa the old way if that would make any difference? Then again, I still wouldn't have a clue how to enable SPDIF output.

I wonder what on earth Red Hat did to get it going?

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tad · Posted: Wed Oct 01, 2003 5:47 pm Post subject:

I checked ALSA's soundcard list, and I don't see your chipset listed. Maybe Red Hat actually used OSS?

cyclocross · Posted: Wed Oct 01, 2003 5:51 pm Post subject:

First thing you should do is check to see if alsa supports spdif out in your driver. Go to the Alsa website and take a look at the matrix. Redhat could have benn using OSS, so that is maybe why it worked there. Also on my sound card(AC97) in my mixer(gnome alsa mixer) I have a check box that will send the analog signal through the spdif. I have a whole bunch of check boxes with cryptic titles just below the volumne slides. I had to experientment with those check boxes to get things running the way I liked.

Best of luck.

raid517 · l33t Joined: 06 Mar 2003 Posts: 946

Thanks guys, but you all keep mentioning OSS, I thought OSS didn't support SPDIF out?

Also I just emerged gnome-alsamixer, and there is no mention there at all of SPDIFor out there either. There is a mention of 'external amplifier power down', but I'm not even quite sure what that means.

It's not looking good I'm afraid...

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krinkle · Posted: Wed Oct 01, 2003 7:54 pm Post subject:

check out this page under the heading "S/PDIF Output" ..http://alsa.opensrc.org/index.php?page=via8233. It looks semi promising... but it still might not work. also to quote the artice

raid517 · l33t Joined: 06 Mar 2003 Posts: 946

Yes thanks, that guide looks useful, but I think I need to deal with the basic gentoo guide first. You see I have now changed alsa support to a module and all subfeatures are now modules too. I did this so that I could more closely follow the gentoo install guide. (All I did was omit the part about actually installing the alsa driver, since the 2.6-test6 kernel already has it installed).

My problem now is much more basic. I need to load my via82xx module, but to do that I need to know what it's called. Unfortunately the kernel helpfile (what there is of it) gives no clue about this.

Also when following the Gentoo alsa guide, one of the instructions is to run 'modules-update'. However whenever I run modules-update I always get an error saying:

raid517 · l33t Joined: 06 Mar 2003 Posts: 946

Well there is something weird going on... I can play DVD's and hear them just fine in Xine by selecting a_52 passthrough. (Which I assume is the same as SPDIF passthrough). So I do know digital out works...

The problem is how to get it to work for the rest of the system?

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thomasando · Tux's lil' helper Joined: 05 Apr 2003 Posts: 94

i had similar problems with my audigy, and again with my onboard sound card which i believe used the same module (can't check now as I'm at work). with the audigy, there was an option in the mixer to enable digital out. I ticked it. worked great! For the onboard card though, it was a bit more tricky than that. There was an option, I think it was maybe IEC9258 or something like that which I ticked, and then I had to adjust the slider for that volume control to 0, and all of a sudden I had a digital output... this was in gnome-alsamixer.

i'll try to remember to confirm the names of these settings for you when i get home

raid517 · l33t Joined: 06 Mar 2003 Posts: 946

Please do. I'm at a loss here. Especially now since even sound in xine has inexplicably dies for no good reason whatsoever too. One minute it was working, and then the next it wasn't.

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