[SOLVED] ALC892 - Unable to get front panel audio working

[raidzero]

EDIT: This has been solved. As usual, once I post a question about something it motivates me to dig further. 9 times out of 10 I end up answering my own question, and thats what I have done here. This post is more of a worklog/brainstorm than anything else now... solution in post 2.

I am running an EVGA x58 FTW3 board, and I cannot make the front panel headphone port work. I have tried kernels 3.2.12, 3.34 & 3.3.5. I am running ALSA with pulseaudio. I have tried pulseaudio version 2.0 as well as 1.1-r1.

The headphone port is just dead. It works in windows (and auto-mutes speakers). In Gentoo it does nothing at all, no sound comes through it and the speakers continue to play sound.

Here is the output of alsa-info: http://www.alsa-project.org/db/?f=6adabb9026d3ce191cadea678cded0e4b8c1e154

Kernel 3.3.5 config (sound-related):

[raidzero]

So I decided to open up /usr/src/linux/sound/pci/hda/patch_realtek.c. I found the text ALC892 in it. It referenced ALC662. I already knew that node 0x1b was my headphone port. I looked in the alc_fixup alc662_fixups struct to find what seemed to be overrides for various pins. I found one with 0x1b as the node id and a comment of "HP out". I figured I would see what happened if I tried to add a quirk entry that attached the PCI ID of my sound card to this struct entry (ALC662_FIXUP_ASUS_MODE2):

[sk3l]

raidzero,

Kudos for your investigation of this issue and the solution you posted. I have the same gear as you (i.e. EVGA x58 mobo w/ ALC892 audio) and I can confirm that the patch you outlined here does in fact work! I was going bonkers for a few days, trying all of the other suggestions you had pointed out in your first post, and with no results to show for it.

Having said that, there are a few drawbacks I seem to have encountered at the end of this exercise. Firstly, now I am now longer able to affect the master volume of the system from the audio controls in Gnome, i.e. pulseaudio. I can drop down to alsamixer and change the volume fine, just not through pulseaudio. Second, the sound quality of the headphones from the front jack are just atrocious. It sounds completely devoid of bass, and may be only output from either L or R channel. I know the headphones are solid, as I use them everyday. To be fair, this could very well be a fault attributable to the HDA header of the case (mine is an Antec 300) or even the mobo connection. Then again, it could be software related in the alsa driver, too. Last, while this patch does the job, I believe that it would need to be applied at each successive kernel upgrade, and this is indeed an onerous chore to need to keep tabs on.

My hope is that 1) a more robust fix that won't inflict collateral damage on pulseaudio and potentially might yield better sound quality could be achieved through a more permanent and tactical change to the kernel code and as a result 2) we wouldn't need to take ownership of patching the source upon each kernel make. In other words, there really ought to be a proper revision to code by "upstream" or whatever one calls the maintainers of the Gentoo kernel code so that it correctly handles the properties of the ALC892 audio codec Is there a way that this issue could be made known to "upstream", through a bug tracker or the like? I'd be happy to do this, it it hasn't yet been done. Pardon a newb's ignorance on the SOP for such a scenario.

Thanks
-Mike

BTW I'm currently running Gentoo kernel 3.3.8 and obviously any enhancements for ALC892 support that might be out there haven't yet made it to the kernel code.

[hedmo]

i have the same problem as you guys .can you help me to patch my kernel to please.
i dont know how to do it.
regards hedmo

[sk3l]

Hi hedmo,

Frankly, I would think twice about patching the kernel to address this unless you are prepared to not be able to adjust volume from your desktop environment (unless that symptom I described is unique to my system) and you are willing to re-apply this patch upon every new kernel release. If you can accept those two cases, then read on.

First thing first, make a copy/backup of the file /usr/src/linux/sound/pci/hda/patch_realtek.c Always do this when modding system files so you can fall back to the original version of the file. I would even go so far as to copy your current kernel image and stash that away, although the risk of patching the sound driver should be somewhat low with regard to adversely impacting your system.

Next you need to apply the changes described by raidzero to the file patch_realtek.c. Basically, his changes have the affect of pairing up the characteristics of our sound codec (ALC892) to the layout of a similar chip configuration presented in the patch_realtek. There are two ways to do this. The easiest way, which is what I chose to do, would be to manually copy and paste these 2 lines from raidzero's first source example and paste them into the patch_realtek.c file. I think the line number you'd want to paste them at is 6617, but this will depend on which version of the file you have. I am away from my home pc right now and can't tell you the exact file number for the source in my kernel 3.3.8. Your best bet would be to search for the token "SND_PCI_QUIRK(0x1b35, 0x2206, "CZC P10T", ALC662_FIXUP_CZC_P10T)," and then put the 2 lines below directly after it.

[hedmo]

sk3l

i still dont get any sound and found the lines i think :



SND_PCI_QUIRK(0x19da, 0xa130, "Zotac Z68", ALC662_FIXUP_ZOTAC_Z68),
SND_PCI_QUIRK(0x1b35, 0x2206, "CZC P10T", ALC662_FIXUP_CZC_P10T),
//added for alc892
SND_PCI_QUIRK(0x8086, 0x3a3e, "EVGA x58 FTW3", ALC662_FIXUP_ASUS_MODE2)$
#if 0


rebuild my kernel,reemerge alsa-driver and reboot.the only thing i can hear is when alsa is starting,a quick and short sound like my mid speaker is jumping one time.thats all

thank you for your post

regards hedmo

[sk3l]

That looks like the appropriate line to paste on. I see a dollar sign "$" at the end of the second line you provided, but the final character needs to be a comma ",". I'm not sure if that's an artifact of your post on this site, or if that's really what was put into the source file, but I'm going to guess the former because the module shouldn't make successfully with a dollar sign there. Out of curiosity what is your motherboard?

I don't have any other suggestions, sorry. Maybe someone else can chime in. If you have a way to boot another distro or Windows on the same machine, I'd recommend checking that you get sound from the jack outside of Gentoo to make sure your case front panel header and motherboard connector are working fine.

-Mike

[hedmo]

[sk3l]

Well, in all likelihood that is your issue right there. radizero and myself both are running EVGA boards. The idea of this patch is to understand that the pin layout of our EVGA mobo's HDA connector resembles certain configurations presented for other similar mobo's in the patch_realtek module, and piggybacking our EVGA boards on that similar HDA pin layout. You cannot make that same assumption using a different board, ASUS in this case.

If you re-flashed your BIOS, then you should go back into the BIOS configuration and ensure that the HDA audio, specifically the front panel, is enabled. I am not familiar with your mobo's BIOS, but I know many of the modern boards have BIOS configuration options pertinent to audio.

-Mike

[hedmo]